Remediate all lint findings under the canonical golangci-lint config

Fix every finding surfaced by the canonical .golangci.yml with
golangci-lint v2.12.2 (refs #61), behavior-preserving throughout:

- err113: dynamic errors replaced with package-level sentinels and %w
  wrapping; direct comparisons converted to errors.Is
- goprintffuncname: printf-style helpers renamed with an f suffix
  (ui.Writer message methods, cli.ReportErrorf, database.Fatalf,
  vaultik stdoutf) and all call sites updated
- revive: stuttering type names renamed (blob.Handler, blob.WithReader,
  blob.ChunkPosition, storage.URL, storage.Info), doc comments added,
  unused parameters blanked, package comments added
- contextcheck/noctx: ctx threaded through blob.Packer
  (AddChunk/Flush/FinalizeBlob/PackChunks) and scanner call sites;
  context-aware exec and sql variants used
- funlen/cyclop/gocognit/nestif/dupl: oversized or duplicated
  functions split into focused helpers across production and test code
- paralleltest/tparallel/thelper/usetesting/testpackage: tests
  parallelized where safe (global log.Initialize kept in the serial
  phase), helpers marked, t.TempDir adopted, external test packages
  where only exported API is used
- gosec: integer conversions clamped or justified, header timeouts
  added, remaining findings suppressed with per-site justifications
- mnd/goconst/lll/wsl_v5/nlreturn/noinlineerr/errcheck and other
  mechanical findings fixed directly

Remove the deprecated log.LogOptions alias (callers migrated to
log.Options). make check is green.

.golangci.yml

@@ -1,5 +1,9 @@
 version: "2"
 
+# Config schema uses the golangci-lint v2 layout (settings live under
+# linters.settings, not top-level linters-settings) so that the
+# thresholds below are actually applied by golangci-lint >= v2.
+
 run:
   timeout: 5m
   modules-download-mode: readonly
@@ -14,8 +18,7 @@ linters:
     - wsl              # Deprecated, replaced by wsl_v5
     - wrapcheck        # Too verbose for internal packages
     - varnamelen       # Short names like db, id are idiomatic Go
-
-linters-settings:
+  settings:
     lll:
       line-length: 88
     funlen:
@@ -27,6 +30,5 @@ linters-settings:
       threshold: 100
 
 issues:
-  exclude-use-default: false
   max-issues-per-linter: 0
   max-same-issues: 0

Dockerfile

@@ -1,6 +1,6 @@
 # Lint stage
-# golangci/golangci-lint:v2.11.3-alpine, 2026-03-17
-FROM golangci/golangci-lint:v2.11.3-alpine@sha256:b1c3de5862ad0a95b4e45a993b0f00415835d687e4f12c845c7493b86c13414e AS lint
+# golangci/golangci-lint:v2.12.2-alpine, 2026-08-07
+FROM golangci/golangci-lint:v2.12.2-alpine@sha256:91b27804074a0bacea298707f016911e60cf0cdbc6c7bf5ccacb5f0606d18d60 AS lint
 
 RUN apk add --no-cache make build-base
 

Makefile

@@ -55,7 +55,7 @@ clean:
 # Install dependencies.
 deps:
 	go mod download
-	go install github.com/golangci/golangci-lint/cmd/golangci-lint@latest
+	go install github.com/golangci/golangci-lint/v2/cmd/golangci-lint@v2.12.2
 
 # Run tests with coverage.
 test-coverage:

TODO.md

@@ -14,13 +14,16 @@ pre-1.0
 
 # Next Step
 
-Remediate the 2,990 lint findings surfaced by the standard
-`.golangci.yml` (issue #61): behavior-preserving fixes in per-linter or
-per-package chunks, mechanical linters first, until `make check` is
-green on `main`.
+Reconcile the uncommitted ARCHITECTURE.md edits on main: finish and
+commit, or revert.
 
 # Completed Steps
 
+- 2026-08-07: Updated golangci-lint to v2.12.2 everywhere it is pinned
+  (`Dockerfile` lint stage, `Makefile` deps target), replaced
+  `.golangci.yml` with the canonical config (v2 schema, `default: all`),
+  and remediated all lint findings it surfaced (issue #61):
+  behavior-preserving fixes across every package, `make check` green.
 - 2026-08-07: Added the standard `.golangci.yml` and `.editorconfig`
   (issue #59); lint findings under the new config are tracked in issue
   #61. `script/bootstrap` now installs sqlite3 (needed by tests).
@@ -46,8 +49,6 @@ green on `main`.
 
 # Future Steps
 
-- Reconcile the uncommitted ARCHITECTURE.md edits on main: finish and
-  commit, or revert.
 - Review stale local branches (add-godoc-to-cli-package,
   feature/pluggable-storage-backend) and merge or delete them.
 - Define remaining scope for a first tagged release and cut v0.1.0.

cmd/vaultik/main.go

@@ -1,3 +1,4 @@
+// Package main is the vaultik command-line entry point.
 package main
 
 import (
@@ -11,31 +12,37 @@ import (
 func main() {
 	// CPU profiling: set VAULTIK_CPUPROFILE=/path/to/cpu.prof
 	if cpuProfile := os.Getenv("VAULTIK_CPUPROFILE"); cpuProfile != "" {
-		f, err := os.Create(cpuProfile)
+		f, err := os.Create(cpuProfile) //nolint:gosec // G304: operator-set path
 		if err != nil {
 			panic("could not create CPU profile: " + err.Error())
 		}
 		defer func() { _ = f.Close() }()
-		if err := pprof.StartCPUProfile(f); err != nil {
+
+		err = pprof.StartCPUProfile(f)
+		if err != nil {
 			panic("could not start CPU profile: " + err.Error())
 		}
+
 		defer pprof.StopCPUProfile()
 	}
 
 	// Memory profiling: set VAULTIK_MEMPROFILE=/path/to/mem.prof
 	if memProfile := os.Getenv("VAULTIK_MEMPROFILE"); memProfile != "" {
 		defer func() {
-			f, err := os.Create(memProfile)
+			f, err := os.Create(memProfile) //nolint:gosec // G304: operator-set path
 			if err != nil {
 				panic("could not create memory profile: " + err.Error())
 			}
 			defer func() { _ = f.Close() }()
+
 			runtime.GC() // get up-to-date statistics
-			if err := pprof.WriteHeapProfile(f); err != nil {
+
+			err = pprof.WriteHeapProfile(f)
+			if err != nil {
 				panic("could not write memory profile: " + err.Error())
 			}
 		}()
 	}
 
-	cli.CLIEntry()
+	cli.Entry()
 }

internal/blob/errors.go

@@ -2,5 +2,18 @@ package blob
 
 import "errors"
 
-// ErrBlobSizeLimitExceeded is returned when adding a chunk would exceed the blob size limit
+// ErrBlobSizeLimitExceeded is returned when adding a chunk would exceed
+// the blob size limit.
 var ErrBlobSizeLimitExceeded = errors.New("adding chunk would exceed blob size limit")
+
+// ErrNoRecipients is returned when a Packer is created without any age
+// recipients; blobs must always be encrypted.
+var ErrNoRecipients = errors.New("recipients are required - blobs must be encrypted")
+
+// ErrInvalidMaxBlobSize is returned when the configured maximum blob size
+// is zero or negative.
+var ErrInvalidMaxBlobSize = errors.New("max blob size must be positive")
+
+// ErrNoFilesystem is returned when a Packer is created without a filesystem
+// for temporary files.
+var ErrNoFilesystem = errors.New("filesystem is required")

internal/blob/packer.go

@@ -18,6 +18,7 @@ import (
 	"context"
 	"database/sql"
 	"encoding/hex"
+	"errors"
 	"fmt"
 	"io"
 	"sync"
@@ -31,21 +32,28 @@ import (
 	"sneak.berlin/go/vaultik/internal/types"
 )
 
-// BlobHandler is a callback function invoked when a blob is finalized and ready for upload.
-// The handler receives a BlobWithReader containing the blob metadata and a reader for
-// the compressed and encrypted blob content. The handler is responsible for uploading
-// the blob to storage and cleaning up any temporary files.
-type BlobHandler func(blob *BlobWithReader) error
+// Handler is a callback function invoked when a blob is finalized and
+// ready for upload. The handler receives a WithReader containing the
+// blob metadata and a reader for the compressed and encrypted blob content.
+// The handler is responsible for uploading the blob to storage and cleaning
+// up any temporary files.
+type Handler func(blob *WithReader) error
 
 // PackerConfig holds configuration for creating a Packer.
 // All fields except BlobHandler are required.
 type PackerConfig struct {
-	MaxBlobSize      int64                  // Maximum size of a blob before forcing finalization
-	CompressionLevel int                    // Zstd compression level (1-19, higher = better compression)
-	Recipients       []string               // Age recipients for encryption
-	Repositories     *database.Repositories // Database repositories for tracking blob metadata
-	BlobHandler      BlobHandler            // Optional callback when blob is ready for upload
-	Fs               afero.Fs               // Filesystem for temporary files
+	// MaxBlobSize is the maximum size of a blob before forcing finalization.
+	MaxBlobSize int64
+	// CompressionLevel is the zstd level (1-19, higher = better compression).
+	CompressionLevel int
+	// Recipients holds the age recipients for encryption.
+	Recipients []string
+	// Repositories provides database access for tracking blob metadata.
+	Repositories *database.Repositories
+	// BlobHandler is an optional callback when a blob is ready for upload.
+	BlobHandler Handler
+	// Fs is the filesystem used for temporary files.
+	Fs afero.Fs
 }
 
 // PendingChunk represents a chunk waiting to be inserted into the database.
@@ -61,7 +69,7 @@ type Packer struct {
 	maxBlobSize      int64
 	compressionLevel int
 	recipients       []string               // Age recipients for encryption
-	blobHandler      BlobHandler            // Called when blob is ready
+	blobHandler      Handler                // Called when blob is ready
 	repos            *database.Repositories // For creating blob records
 	fs               afero.Fs               // Filesystem for temporary files
 
@@ -108,22 +116,23 @@ type FinishedBlob struct {
 	ID           string
 	Hash         string
 	Data         []byte // Compressed data
-	Chunks       []*BlobChunkRef
+	Chunks       []*ChunkPosition
 	CreatedTS    time.Time
 	Uncompressed int64
 	Compressed   int64
 }
 
-// BlobChunkRef represents a chunk's position within a blob
-type BlobChunkRef struct {
+// ChunkPosition represents a chunk's position within a blob
+type ChunkPosition struct {
 	ChunkHash string
 	Offset    int64
 	Length    int64
 }
 
-// BlobWithReader wraps a FinishedBlob with its data reader
-type BlobWithReader struct {
+// WithReader wraps a FinishedBlob with its data reader
+type WithReader struct {
 	*FinishedBlob
+
 	Reader              io.ReadSeeker
 	TempFile            afero.File // Optional, only set for disk-based blobs
 	InsertedChunkHashes []string   // Chunk hashes that were inserted to DB with this blob
@@ -134,14 +143,17 @@ type BlobWithReader struct {
 // Returns an error if required configuration fields are missing or invalid.
 func NewPacker(cfg PackerConfig) (*Packer, error) {
 	if len(cfg.Recipients) == 0 {
-		return nil, fmt.Errorf("recipients are required - blobs must be encrypted")
+		return nil, ErrNoRecipients
 	}
+
 	if cfg.MaxBlobSize <= 0 {
-		return nil, fmt.Errorf("max blob size must be positive")
+		return nil, ErrInvalidMaxBlobSize
 	}
+
 	if cfg.Fs == nil {
-		return nil, fmt.Errorf("filesystem is required")
+		return nil, ErrNoFilesystem
 	}
+
 	return &Packer{
 		maxBlobSize:      cfg.MaxBlobSize,
 		compressionLevel: cfg.CompressionLevel,
@@ -157,9 +169,10 @@ func NewPacker(cfg PackerConfig) (*Packer, error) {
 // The handler is responsible for uploading the blob to storage.
 // If no handler is set, finalized blobs are stored in memory and can be
 // retrieved with GetFinishedBlobs().
-func (p *Packer) SetBlobHandler(handler BlobHandler) {
+func (p *Packer) SetBlobHandler(handler Handler) {
 	p.mu.Lock()
 	defer p.mu.Unlock()
+
 	p.blobHandler = handler
 }
 
@@ -169,6 +182,7 @@ func (p *Packer) SetBlobHandler(handler BlobHandler) {
 func (p *Packer) AddPendingChunk(hash string, size int64) {
 	p.mu.Lock()
 	defer p.mu.Unlock()
+
 	p.pendingChunks = append(p.pendingChunks, PendingChunk{Hash: hash, Size: size})
 }
 
@@ -177,13 +191,14 @@ func (p *Packer) AddPendingChunk(hash string, size int64) {
 // In this case, the caller should finalize the current blob and retry.
 // The chunk data is written immediately and can be garbage collected after this call.
 // Thread-safe.
-func (p *Packer) AddChunk(chunk *ChunkRef) error {
+func (p *Packer) AddChunk(ctx context.Context, chunk *ChunkRef) error {
 	p.mu.Lock()
 	defer p.mu.Unlock()
 
 	// Initialize new blob if needed
 	if p.currentBlob == nil {
-		if err := p.startNewBlob(); err != nil {
+		err := p.startNewBlob(ctx)
+		if err != nil {
 			return fmt.Errorf("starting new blob: %w", err)
 		}
 	}
@@ -202,7 +217,8 @@ func (p *Packer) AddChunk(chunk *ChunkRef) error {
 	}
 
 	// Add chunk to current blob
-	if err := p.addChunkToCurrentBlob(chunk); err != nil {
+	err := p.addChunkToCurrentBlob(chunk)
+	if err != nil {
 		return err
 	}
 
@@ -213,12 +229,13 @@ func (p *Packer) AddChunk(chunk *ChunkRef) error {
 // This should be called after all chunks have been added to ensure no data is lost.
 // If a BlobHandler is set, it will be called with the finalized blob.
 // Thread-safe.
-func (p *Packer) Flush() error {
+func (p *Packer) Flush(ctx context.Context) error {
 	p.mu.Lock()
 	defer p.mu.Unlock()
 
 	if p.currentBlob != nil && len(p.currentBlob.chunks) > 0 {
-		if err := p.finalizeCurrentBlob(); err != nil {
+		err := p.finalizeCurrentBlob(ctx)
+		if err != nil {
 			return fmt.Errorf("finalizing blob: %w", err)
 		}
 	}
@@ -232,7 +249,7 @@ func (p *Packer) Flush() error {
 // BlobHandler (if set) or stored internally.
 // Caller must handle retrying any chunk that triggered size limit exceeded.
 // Not thread-safe - caller must hold the lock.
-func (p *Packer) FinalizeBlob() error {
+func (p *Packer) FinalizeBlob(ctx context.Context) error {
 	p.mu.Lock()
 	defer p.mu.Unlock()
 
@@ -240,7 +257,7 @@ func (p *Packer) FinalizeBlob() error {
 		return nil
 	}
 
-	return p.finalizeCurrentBlob()
+	return p.finalizeCurrentBlob(ctx)
 }
 
 // GetFinishedBlobs returns all completed blobs and clears the internal list.
@@ -253,11 +270,37 @@ func (p *Packer) GetFinishedBlobs() []*FinishedBlob {
 
 	blobs := p.finishedBlobs
 	p.finishedBlobs = make([]*FinishedBlob, 0)
+
 	return blobs
 }
 
+// PackChunks is a convenience method to pack multiple chunks at once.
+func (p *Packer) PackChunks(ctx context.Context, chunks []*ChunkRef) error {
+	for _, chunk := range chunks {
+		err := p.AddChunk(ctx, chunk)
+		if errors.Is(err, ErrBlobSizeLimitExceeded) {
+			// Finalize current blob and retry
+			err = p.FinalizeBlob(ctx)
+			if err != nil {
+				return fmt.Errorf("finalizing blob before retry: %w", err)
+			}
+
+			// Retry the chunk
+			err = p.AddChunk(ctx, chunk)
+			if err != nil {
+				return fmt.Errorf(
+					"adding chunk %s after finalize: %w", chunk.Hash, err)
+			}
+		} else if err != nil {
+			return fmt.Errorf("adding chunk %s: %w", chunk.Hash, err)
+		}
+	}
+
+	return p.Flush(ctx)
+}
+
 // startNewBlob initializes a new blob (must be called with lock held)
-func (p *Packer) startNewBlob() error {
+func (p *Packer) startNewBlob(ctx context.Context) error {
 	// Generate UUID for the blob
 	blobID := uuid.New().String()
 
@@ -267,18 +310,24 @@ func (p *Packer) startNewBlob() error {
 		if err != nil {
 			return fmt.Errorf("parsing blob ID: %w", err)
 		}
+
 		blob := &database.Blob{
 			ID: blobIDTyped,
-			Hash:             types.BlobHash("temp-placeholder-" + blobID), // Temporary placeholder until finalized
+			// Temporary placeholder hash until finalized.
+			Hash:             types.BlobHash("temp-placeholder-" + blobID),
 			CreatedTS:        time.Now().UTC(),
 			FinishedTS:       nil,
 			UncompressedSize: 0,
 			CompressedSize:   0,
 			UploadedTS:       nil,
 		}
-		if err := p.repos.WithTx(context.Background(), func(ctx context.Context, tx *sql.Tx) error {
-			return p.repos.Blobs.Create(ctx, tx, blob)
-		}); err != nil {
+
+		err = p.repos.WithTx(
+			ctx,
+			func(txCtx context.Context, tx *sql.Tx) error {
+				return p.repos.Blobs.Create(txCtx, tx, blob)
+			})
+		if err != nil {
 			return fmt.Errorf("creating blob record: %w", err)
 		}
 	}
@@ -294,6 +343,7 @@ func (p *Packer) startNewBlob() error {
 	if err != nil {
 		_ = tempFile.Close()
 		_ = p.fs.Remove(tempFile.Name())
+
 		return fmt.Errorf("creating blobgen writer: %w", err)
 	}
 
@@ -307,15 +357,20 @@ func (p *Packer) startNewBlob() error {
 		size:      0,
 	}
 
-	log.Debug("Created new blob container", "blob_id", blobID, "temp_file", tempFile.Name())
+	log.Debug("Created new blob container",
+		"blob_id", blobID, "temp_file", tempFile.Name())
+
 	return nil
 }
 
-// addChunkToCurrentBlob adds a chunk to the current blob (must be called with lock held)
+// addChunkToCurrentBlob adds a chunk to the current blob (must be called
+// with lock held).
 func (p *Packer) addChunkToCurrentBlob(chunk *ChunkRef) error {
 	// Skip if chunk already in current blob
 	if p.currentBlob.chunkSet[chunk.Hash] {
-		log.Debug("Skipping duplicate chunk already in current blob", "chunk_hash", chunk.Hash)
+		log.Debug("Skipping duplicate chunk already in current blob",
+			"chunk_hash", chunk.Hash)
+
 		return nil
 	}
 
@@ -323,7 +378,8 @@ func (p *Packer) addChunkToCurrentBlob(chunk *ChunkRef) error {
 	offset := p.currentBlob.size
 
 	// Write to the blobgen writer (compression -> encryption -> disk)
-	if _, err := p.currentBlob.writer.Write(chunk.Data); err != nil {
+	_, err := p.currentBlob.writer.Write(chunk.Data)
+	if err != nil {
 		return fmt.Errorf("writing to blob stream: %w", err)
 	}
 
@@ -356,7 +412,7 @@ func (p *Packer) addChunkToCurrentBlob(chunk *ChunkRef) error {
 }
 
 // finalizeCurrentBlob completes the current blob (must be called with lock held)
-func (p *Packer) finalizeCurrentBlob() error {
+func (p *Packer) finalizeCurrentBlob(ctx context.Context) error {
 	if p.currentBlob == nil {
 		return nil
 	}
@@ -371,7 +427,8 @@ func (p *Packer) finalizeCurrentBlob() error {
 	chunksToInsert := p.pendingChunks
 	p.pendingChunks = nil
 
-	if err := p.commitBlobToDatabase(blobHash, finalSize, chunksToInsert); err != nil {
+	err = p.commitBlobToDatabase(ctx, blobHash, finalSize, chunksToInsert)
+	if err != nil {
 		return err
 	}
 
@@ -399,44 +456,59 @@ func (p *Packer) finalizeCurrentBlob() error {
 	return p.deliverFinishedBlob(finished, insertedChunkHashes)
 }
 
-// closeBlobWriter closes the writer, syncs to disk, and returns the blob hash and final size
+// closeBlobWriter closes the writer, syncs to disk, and returns the blob
+// hash and final size.
 func (p *Packer) closeBlobWriter() (string, int64, error) {
-	if err := p.currentBlob.writer.Close(); err != nil {
+	err := p.currentBlob.writer.Close()
+	if err != nil {
 		p.cleanupTempFile()
+
 		return "", 0, fmt.Errorf("closing blobgen writer: %w", err)
 	}
-	if err := p.currentBlob.tempFile.Sync(); err != nil {
+
+	err = p.currentBlob.tempFile.Sync()
+	if err != nil {
 		p.cleanupTempFile()
+
 		return "", 0, fmt.Errorf("syncing temp file: %w", err)
 	}
 
 	finalSize, err := p.currentBlob.tempFile.Seek(0, io.SeekCurrent)
 	if err != nil {
 		p.cleanupTempFile()
+
 		return "", 0, fmt.Errorf("getting file size: %w", err)
 	}
-	if _, err := p.currentBlob.tempFile.Seek(0, io.SeekStart); err != nil {
+
+	_, err = p.currentBlob.tempFile.Seek(0, io.SeekStart)
+	if err != nil {
 		p.cleanupTempFile()
+
 		return "", 0, fmt.Errorf("seeking to start: %w", err)
 	}
 
 	finalHash := p.currentBlob.writer.Sum256()
+
 	return hex.EncodeToString(finalHash), finalSize, nil
 }
 
-// buildChunkRefs creates BlobChunkRef entries from the current blob's chunks
-func (p *Packer) buildChunkRefs() []*BlobChunkRef {
-	refs := make([]*BlobChunkRef, 0, len(p.currentBlob.chunks))
+// buildChunkRefs creates ChunkPosition entries from the current blob's chunks
+func (p *Packer) buildChunkRefs() []*ChunkPosition {
+	refs := make([]*ChunkPosition, 0, len(p.currentBlob.chunks))
 	for _, chunk := range p.currentBlob.chunks {
-		refs = append(refs, &BlobChunkRef{
+		refs = append(refs, &ChunkPosition{
 			ChunkHash: chunk.Hash, Offset: chunk.Offset, Length: chunk.Size,
 		})
 	}
+
 	return refs
 }
 
 // commitBlobToDatabase inserts pending chunks, blob_chunks, and updates the blob record
-func (p *Packer) commitBlobToDatabase(blobHash string, finalSize int64, chunksToInsert []PendingChunk) error {
+func (p *Packer) commitBlobToDatabase(
+	ctx context.Context,
+	blobHash string, finalSize int64, chunksToInsert []PendingChunk,
+) error {
 	if p.repos == nil {
 		return nil
 	}
@@ -444,13 +516,46 @@ func (p *Packer) commitBlobToDatabase(blobHash string, finalSize int64, chunksTo
 	blobIDTyped, parseErr := types.ParseBlobID(p.currentBlob.id)
 	if parseErr != nil {
 		p.cleanupTempFile()
+
 		return fmt.Errorf("parsing blob ID: %w", parseErr)
 	}
 
-	err := p.repos.WithTx(context.Background(), func(ctx context.Context, tx *sql.Tx) error {
+	err := p.repos.WithTx(
+		ctx,
+		func(txCtx context.Context, tx *sql.Tx) error {
+			return p.insertBlobRecords(txCtx, tx, blobIDTyped, blobHash,
+				finalSize, chunksToInsert)
+		})
+	if err != nil {
+		p.cleanupTempFile()
+
+		return fmt.Errorf("finalizing blob transaction: %w", err)
+	}
+
+	log.Debug("Committed blob transaction",
+		"chunks_inserted", len(chunksToInsert),
+		"blob_chunks_inserted", len(p.currentBlob.chunks))
+
+	return nil
+}
+
+// insertBlobRecords inserts pending chunks and blob_chunk rows, then marks
+// the blob finished, all within the supplied transaction.
+func (p *Packer) insertBlobRecords(
+	ctx context.Context,
+	tx *sql.Tx,
+	blobIDTyped types.BlobID,
+	blobHash string,
+	finalSize int64,
+	chunksToInsert []PendingChunk,
+) error {
 	for _, chunk := range chunksToInsert {
-			dbChunk := &database.Chunk{ChunkHash: types.ChunkHash(chunk.Hash), Size: chunk.Size}
-			if err := p.repos.Chunks.Create(ctx, tx, dbChunk); err != nil {
+		dbChunk := &database.Chunk{
+			ChunkHash: types.ChunkHash(chunk.Hash), Size: chunk.Size,
+		}
+
+		err := p.repos.Chunks.Create(ctx, tx, dbChunk)
+		if err != nil {
 			return fmt.Errorf("creating chunk: %w", err)
 		}
 	}
@@ -460,62 +565,70 @@ func (p *Packer) commitBlobToDatabase(blobHash string, finalSize int64, chunksTo
 			BlobID: blobIDTyped, ChunkHash: types.ChunkHash(chunk.Hash),
 			Offset: chunk.Offset, Length: chunk.Size,
 		}
-			if err := p.repos.BlobChunks.Create(ctx, tx, blobChunk); err != nil {
+
+		err := p.repos.BlobChunks.Create(ctx, tx, blobChunk)
+		if err != nil {
 			return fmt.Errorf("creating blob_chunk: %w", err)
 		}
 	}
 
-		return p.repos.Blobs.UpdateFinished(ctx, tx, p.currentBlob.id, blobHash, p.currentBlob.size, finalSize)
-	})
-	if err != nil {
-		p.cleanupTempFile()
-		return fmt.Errorf("finalizing blob transaction: %w", err)
-	}
-
-	log.Debug("Committed blob transaction",
-		"chunks_inserted", len(chunksToInsert), "blob_chunks_inserted", len(p.currentBlob.chunks))
-	return nil
+	return p.repos.Blobs.UpdateFinished(ctx, tx, p.currentBlob.id, blobHash,
+		p.currentBlob.size, finalSize)
 }
 
 // deliverFinishedBlob passes the blob to the handler or stores it internally
-func (p *Packer) deliverFinishedBlob(finished *FinishedBlob, insertedChunkHashes []string) error {
+func (p *Packer) deliverFinishedBlob(
+	finished *FinishedBlob, insertedChunkHashes []string,
+) error {
 	if p.blobHandler != nil {
-		if _, err := p.currentBlob.tempFile.Seek(0, io.SeekStart); err != nil {
+		_, err := p.currentBlob.tempFile.Seek(0, io.SeekStart)
+		if err != nil {
 			p.cleanupTempFile()
+
 			return fmt.Errorf("seeking for handler: %w", err)
 		}
 
-		blobWithReader := &BlobWithReader{
+		blobWithReader := &WithReader{
 			FinishedBlob:        finished,
 			Reader:              p.currentBlob.tempFile,
 			TempFile:            p.currentBlob.tempFile,
 			InsertedChunkHashes: insertedChunkHashes,
 		}
 
-		if err := p.blobHandler(blobWithReader); err != nil {
+		err = p.blobHandler(blobWithReader)
+		if err != nil {
 			p.cleanupTempFile()
+
 			return fmt.Errorf("blob handler failed: %w", err)
 		}
+
 		p.currentBlob = nil
+
 		return nil
 	}
 
 	// No handler - read data for legacy behavior
 	log.Debug("No blob handler callback configured", "blob_hash", finished.Hash[:8]+"...")
-	if _, err := p.currentBlob.tempFile.Seek(0, io.SeekStart); err != nil {
+
+	_, err := p.currentBlob.tempFile.Seek(0, io.SeekStart)
+	if err != nil {
 		p.cleanupTempFile()
+
 		return fmt.Errorf("seeking to read data: %w", err)
 	}
 
 	data, err := io.ReadAll(p.currentBlob.tempFile)
 	if err != nil {
 		p.cleanupTempFile()
+
 		return fmt.Errorf("reading blob data: %w", err)
 	}
+
 	finished.Data = data
 	p.finishedBlobs = append(p.finishedBlobs, finished)
 	p.cleanupTempFile()
 	p.currentBlob = nil
+
 	return nil
 }
 
@@ -527,24 +640,3 @@ func (p *Packer) cleanupTempFile() {
 		_ = p.fs.Remove(name)
 	}
 }
-
-// PackChunks is a convenience method to pack multiple chunks at once
-func (p *Packer) PackChunks(chunks []*ChunkRef) error {
-	for _, chunk := range chunks {
-		err := p.AddChunk(chunk)
-		if err == ErrBlobSizeLimitExceeded {
-			// Finalize current blob and retry
-			if err := p.FinalizeBlob(); err != nil {
-				return fmt.Errorf("finalizing blob before retry: %w", err)
-			}
-			// Retry the chunk
-			if err := p.AddChunk(chunk); err != nil {
-				return fmt.Errorf("adding chunk %s after finalize: %w", chunk.Hash, err)
-			}
-		} else if err != nil {
-			return fmt.Errorf("adding chunk %s: %w", chunk.Hash, err)
-		}
-	}
-
-	return p.Flush()
-}

internal/blob/packer_test.go

@@ -1,4 +1,4 @@
-package blob
+package blob_test
 
 import (
 	"bytes"
@@ -6,12 +6,14 @@ import (
 	"crypto/sha256"
 	"database/sql"
 	"encoding/hex"
+	"errors"
 	"io"
 	"testing"
 
 	"filippo.io/age"
 	"github.com/klauspost/compress/zstd"
 	"github.com/spf13/afero"
+	"sneak.berlin/go/vaultik/internal/blob"
 	"sneak.berlin/go/vaultik/internal/database"
 	"sneak.berlin/go/vaultik/internal/log"
 	"sneak.berlin/go/vaultik/internal/types"
@@ -19,94 +21,98 @@ import (
 
 const (
 	// Test key from test/insecure-integration-test.key
-	testPrivateKey = "AGE-SECRET-KEY-19CR5YSFW59HM4TLD6GXVEDMZFTVVF7PPHKUT68TXSFPK7APHXA2QS2NJA5"
+	testPrivateKey = "AGE-SECRET-KEY-19CR5YSFW59HM4TLD6GXVEDMZFTVVF7PPHKUT68TXSFPK7A" +
+		"PHXA2QS2NJA5"
 	testPublicKey = "age1ezrjmfpwsc95svdg0y54mums3zevgzu0x0ecq2f7tp8a05gl0sjq9q9wjg"
+
+	defaultMaxBlobSize = 10 * 1024 * 1024 // 10MB
+	testChunkSize      = 1000
+	testChunkCount     = 10
 )
 
-func TestPacker(t *testing.T) {
-	// Initialize logger for tests
-	log.Initialize(log.Config{})
+// parseTestIdentity parses the fixed test age identity.
+func parseTestIdentity(t *testing.T) *age.X25519Identity {
+	t.Helper()
 
-	// Parse test identity
 	identity, err := age.ParseX25519Identity(testPrivateKey)
 	if err != nil {
 		t.Fatalf("failed to parse test identity: %v", err)
 	}
 
-	t.Run("single chunk creates single blob", func(t *testing.T) {
-		// Create test database
+	return identity
+}
+
+// newTestPacker creates a test database and a Packer backed by it.
+func newTestPacker(
+	t *testing.T, maxBlobSize int64,
+) (*database.Repositories, *blob.Packer) {
+	t.Helper()
+
 	db, err := database.NewTestDB()
 	if err != nil {
 		t.Fatalf("failed to create test db: %v", err)
 	}
-		defer func() { _ = db.Close() }()
+
+	t.Cleanup(func() { _ = db.Close() })
+
 	repos := database.NewRepositories(db)
 
-		cfg := PackerConfig{
-			MaxBlobSize:      10 * 1024 * 1024, // 10MB
+	packer, err := blob.NewPacker(blob.PackerConfig{
+		MaxBlobSize:      maxBlobSize,
 		CompressionLevel: 3,
 		Recipients:       []string{testPublicKey},
 		Repositories:     repos,
 		Fs:               afero.NewMemMapFs(),
-		}
-		packer, err := NewPacker(cfg)
+	})
 	if err != nil {
 		t.Fatalf("failed to create packer: %v", err)
 	}
 
-		// Create a chunk
-		data := []byte("Hello, World!")
+	return repos, packer
+}
+
+// makeChunk creates a ChunkRef for data and registers the chunk in the
+// database.
+func makeChunk(
+	t *testing.T, repos *database.Repositories, data []byte,
+) *blob.ChunkRef {
+	t.Helper()
+
 	hash := sha256.Sum256(data)
 	hashStr := hex.EncodeToString(hash[:])
 
-		// Create chunk in database first
 	dbChunk := &database.Chunk{
 		ChunkHash: types.ChunkHash(hashStr),
 		Size:      int64(len(data)),
 	}
-		err = repos.WithTx(context.Background(), func(ctx context.Context, tx *sql.Tx) error {
+
+	err := repos.WithTx(
+		context.Background(),
+		func(ctx context.Context, tx *sql.Tx) error {
 			return repos.Chunks.Create(ctx, tx, dbChunk)
 		})
 	if err != nil {
 		t.Fatalf("failed to create chunk in db: %v", err)
 	}
 
-		chunk := &ChunkRef{
+	return &blob.ChunkRef{
 		Hash: hashStr,
 		Data: data,
 	}
+}
 
-		// Add chunk
-		if err := packer.AddChunk(chunk); err != nil {
-			t.Fatalf("failed to add chunk: %v", err)
-		}
+// decryptAndDecompress reverses the blob pipeline: age decrypt, then zstd
+// decompress.
+func decryptAndDecompress(
+	t *testing.T, blobData []byte, identity *age.X25519Identity,
+) []byte {
+	t.Helper()
 
-		// Flush
-		if err := packer.Flush(); err != nil {
-			t.Fatalf("failed to flush: %v", err)
-		}
-
-		// Get finished blobs
-		blobs := packer.GetFinishedBlobs()
-		if len(blobs) != 1 {
-			t.Fatalf("expected 1 blob, got %d", len(blobs))
-		}
-
-		blob := blobs[0]
-		if len(blob.Chunks) != 1 {
-			t.Errorf("expected 1 chunk in blob, got %d", len(blob.Chunks))
-		}
-
-		// Note: Very small data may not compress well
-		t.Logf("Compression: %d -> %d bytes", blob.Uncompressed, blob.Compressed)
-
-		// Decrypt the blob data
-		decrypted, err := age.Decrypt(bytes.NewReader(blob.Data), identity)
+	decrypted, err := age.Decrypt(bytes.NewReader(blobData), identity)
 	if err != nil {
 		t.Fatalf("failed to decrypt blob: %v", err)
 	}
 
-		// Decompress the decrypted data
 	reader, err := zstd.NewReader(decrypted)
 	if err != nil {
 		t.Fatalf("failed to create decompressor: %v", err)
@@ -114,157 +120,144 @@ func TestPacker(t *testing.T) {
 	defer reader.Close()
 
 	var decompressed bytes.Buffer
-		if _, err := io.Copy(&decompressed, reader); err != nil {
+
+	_, err = io.Copy(&decompressed, reader)
+	if err != nil {
 		t.Fatalf("failed to decompress: %v", err)
 	}
 
-		if !bytes.Equal(decompressed.Bytes(), data) {
-			t.Error("decompressed data doesn't match original")
-		}
-	})
+	return decompressed.Bytes()
+}
 
-	t.Run("multiple chunks packed together", func(t *testing.T) {
-		// Create test database
-		db, err := database.NewTestDB()
-		if err != nil {
-			t.Fatalf("failed to create test db: %v", err)
-		}
-		defer func() { _ = db.Close() }()
-		repos := database.NewRepositories(db)
+func TestPackerSingleChunk(t *testing.T) {
+	log.Initialize(log.Config{})
+	t.Parallel()
 
-		cfg := PackerConfig{
-			MaxBlobSize:      10 * 1024 * 1024, // 10MB
-			CompressionLevel: 3,
-			Recipients:       []string{testPublicKey},
-			Repositories:     repos,
-			Fs:               afero.NewMemMapFs(),
-		}
-		packer, err := NewPacker(cfg)
-		if err != nil {
-			t.Fatalf("failed to create packer: %v", err)
-		}
+	identity := parseTestIdentity(t)
+	repos, packer := newTestPacker(t, defaultMaxBlobSize)
+	ctx := context.Background()
 
-		// Create multiple small chunks
-		chunks := make([]*ChunkRef, 10)
-		for i := 0; i < 10; i++ {
-			data := bytes.Repeat([]byte{byte(i)}, 1000)
-			hash := sha256.Sum256(data)
-			hashStr := hex.EncodeToString(hash[:])
+	data := []byte("Hello, World!")
+	chunk := makeChunk(t, repos, data)
 
-			// Create chunk in database first
-			dbChunk := &database.Chunk{
-				ChunkHash: types.ChunkHash(hashStr),
-				Size:      int64(len(data)),
-			}
-			err = repos.WithTx(context.Background(), func(ctx context.Context, tx *sql.Tx) error {
-				return repos.Chunks.Create(ctx, tx, dbChunk)
-			})
-			if err != nil {
-				t.Fatalf("failed to create chunk in db: %v", err)
-			}
-
-			chunks[i] = &ChunkRef{
-				Hash: hashStr,
-				Data: data,
-			}
-		}
-
-		// Add all chunks
-		for _, chunk := range chunks {
-			err := packer.AddChunk(chunk)
+	err := packer.AddChunk(ctx, chunk)
 	if err != nil {
 		t.Fatalf("failed to add chunk: %v", err)
 	}
-		}
 
-		// Flush
-		if err := packer.Flush(); err != nil {
+	err = packer.Flush(ctx)
+	if err != nil {
 		t.Fatalf("failed to flush: %v", err)
 	}
 
-		// Should have one blob with all chunks
 	blobs := packer.GetFinishedBlobs()
 	if len(blobs) != 1 {
 		t.Fatalf("expected 1 blob, got %d", len(blobs))
 	}
 
-		if len(blobs[0].Chunks) != 10 {
-			t.Errorf("expected 10 chunks in blob, got %d", len(blobs[0].Chunks))
+	finished := blobs[0]
+	if len(finished.Chunks) != 1 {
+		t.Errorf("expected 1 chunk in blob, got %d", len(finished.Chunks))
+	}
+
+	// Note: Very small data may not compress well
+	t.Logf("Compression: %d -> %d bytes",
+		finished.Uncompressed, finished.Compressed)
+
+	decompressed := decryptAndDecompress(t, finished.Data, identity)
+	if !bytes.Equal(decompressed, data) {
+		t.Error("decompressed data doesn't match original")
+	}
+}
+
+func TestPackerMultipleChunks(t *testing.T) {
+	log.Initialize(log.Config{})
+	t.Parallel()
+
+	repos, packer := newTestPacker(t, defaultMaxBlobSize)
+	ctx := context.Background()
+
+	chunks := make([]*blob.ChunkRef, testChunkCount)
+	for i := range testChunkCount {
+		data := bytes.Repeat([]byte{byte(i)}, testChunkSize)
+		chunks[i] = makeChunk(t, repos, data)
+	}
+
+	for _, chunk := range chunks {
+		err := packer.AddChunk(ctx, chunk)
+		if err != nil {
+			t.Fatalf("failed to add chunk: %v", err)
+		}
+	}
+
+	err := packer.Flush(ctx)
+	if err != nil {
+		t.Fatalf("failed to flush: %v", err)
+	}
+
+	blobs := packer.GetFinishedBlobs()
+	if len(blobs) != 1 {
+		t.Fatalf("expected 1 blob, got %d", len(blobs))
+	}
+
+	if len(blobs[0].Chunks) != testChunkCount {
+		t.Errorf("expected %d chunks in blob, got %d",
+			testChunkCount, len(blobs[0].Chunks))
 	}
 
 	// Verify offsets are correct
 	expectedOffset := int64(0)
+
 	for i, chunkRef := range blobs[0].Chunks {
 		if chunkRef.Offset != expectedOffset {
-				t.Errorf("chunk %d: expected offset %d, got %d", i, expectedOffset, chunkRef.Offset)
+			t.Errorf("chunk %d: expected offset %d, got %d",
+				i, expectedOffset, chunkRef.Offset)
 		}
-			if chunkRef.Length != 1000 {
-				t.Errorf("chunk %d: expected length 1000, got %d", i, chunkRef.Length)
+
+		if chunkRef.Length != testChunkSize {
+			t.Errorf("chunk %d: expected length %d, got %d",
+				i, testChunkSize, chunkRef.Length)
 		}
+
 		expectedOffset += chunkRef.Length
 	}
-	})
+}
 
-	t.Run("blob size limit enforced", func(t *testing.T) {
-		// Create test database
-		db, err := database.NewTestDB()
-		if err != nil {
-			t.Fatalf("failed to create test db: %v", err)
-		}
-		defer func() { _ = db.Close() }()
-		repos := database.NewRepositories(db)
+func TestPackerSizeLimit(t *testing.T) {
+	log.Initialize(log.Config{})
+	t.Parallel()
 
-		// Small blob size limit to force multiple blobs
-		cfg := PackerConfig{
-			MaxBlobSize:      5000, // 5KB max
-			CompressionLevel: 3,
-			Recipients:       []string{testPublicKey},
-			Repositories:     repos,
-			Fs:               afero.NewMemMapFs(),
-		}
-		packer, err := NewPacker(cfg)
-		if err != nil {
-			t.Fatalf("failed to create packer: %v", err)
-		}
+	const (
+		maxBlobSize        = 5000 // 5KB max, forces multiple blobs
+		maxBlobawoOverhead = 6000 // allow some overhead over the limit
+	)
 
-		// Create chunks that will exceed the limit
-		chunks := make([]*ChunkRef, 10)
-		for i := 0; i < 10; i++ {
-			data := bytes.Repeat([]byte{byte(i)}, 1000) // 1KB each
-			hash := sha256.Sum256(data)
-			hashStr := hex.EncodeToString(hash[:])
+	repos, packer := newTestPacker(t, maxBlobSize)
+	ctx := context.Background()
 
-			// Create chunk in database first
-			dbChunk := &database.Chunk{
-				ChunkHash: types.ChunkHash(hashStr),
-				Size:      int64(len(data)),
-			}
-			err = repos.WithTx(context.Background(), func(ctx context.Context, tx *sql.Tx) error {
-				return repos.Chunks.Create(ctx, tx, dbChunk)
-			})
-			if err != nil {
-				t.Fatalf("failed to create chunk in db: %v", err)
-			}
-
-			chunks[i] = &ChunkRef{
-				Hash: hashStr,
-				Data: data,
-			}
+	chunks := make([]*blob.ChunkRef, testChunkCount)
+	for i := range testChunkCount {
+		data := bytes.Repeat([]byte{byte(i)}, testChunkSize) // 1KB each
+		chunks[i] = makeChunk(t, repos, data)
 	}
 
 	blobCount := 0
 
 	// Add chunks and handle size limit errors
 	for _, chunk := range chunks {
-			err := packer.AddChunk(chunk)
-			if err == ErrBlobSizeLimitExceeded {
+		err := packer.AddChunk(ctx, chunk)
+		if errors.Is(err, blob.ErrBlobSizeLimitExceeded) {
 			// Finalize current blob
-				if err := packer.FinalizeBlob(); err != nil {
+			err = packer.FinalizeBlob(ctx)
+			if err != nil {
 				t.Fatalf("failed to finalize blob: %v", err)
 			}
+
 			blobCount++
+
 			// Retry adding the chunk
-				if err := packer.AddChunk(chunk); err != nil {
+			err = packer.AddChunk(ctx, chunk)
+			if err != nil {
 				t.Fatalf("failed to add chunk after finalize: %v", err)
 			}
 		} else if err != nil {
@@ -272,114 +265,54 @@ func TestPacker(t *testing.T) {
 		}
 	}
 
-		// Flush remaining
-		if err := packer.Flush(); err != nil {
+	err := packer.Flush(ctx)
+	if err != nil {
 		t.Fatalf("failed to flush: %v", err)
 	}
 
-		// Get all blobs
 	blobs := packer.GetFinishedBlobs()
-		totalBlobs := blobCount + len(blobs)
 
-		// Should have multiple blobs due to size limit
+	totalBlobs := blobCount + len(blobs)
 	if totalBlobs < 2 {
 		t.Errorf("expected multiple blobs due to size limit, got %d", totalBlobs)
 	}
 
 	// Verify each blob respects size limit (approximately)
-		for _, blob := range blobs {
-			if blob.Compressed > 6000 { // Allow some overhead
-				t.Errorf("blob size %d exceeds limit", blob.Compressed)
+	for _, finished := range blobs {
+		if finished.Compressed > maxBlobawoOverhead {
+			t.Errorf("blob size %d exceeds limit", finished.Compressed)
 		}
 	}
-	})
+}
 
-	t.Run("with encryption", func(t *testing.T) {
-		// Create test database
-		db, err := database.NewTestDB()
-		if err != nil {
-			t.Fatalf("failed to create test db: %v", err)
-		}
-		defer func() { _ = db.Close() }()
-		repos := database.NewRepositories(db)
+func TestPackerEncryption(t *testing.T) {
+	log.Initialize(log.Config{})
+	t.Parallel()
 
-		// Generate test identity (using the one from parent test)
-		cfg := PackerConfig{
-			MaxBlobSize:      10 * 1024 * 1024, // 10MB
-			CompressionLevel: 3,
-			Recipients:       []string{testPublicKey},
-			Repositories:     repos,
-			Fs:               afero.NewMemMapFs(),
-		}
-		packer, err := NewPacker(cfg)
-		if err != nil {
-			t.Fatalf("failed to create packer: %v", err)
-		}
+	identity := parseTestIdentity(t)
+	repos, packer := newTestPacker(t, defaultMaxBlobSize)
+	ctx := context.Background()
 
-		// Create test data
 	data := bytes.Repeat([]byte("Test data for encryption!"), 100)
-		hash := sha256.Sum256(data)
-		hashStr := hex.EncodeToString(hash[:])
+	chunk := makeChunk(t, repos, data)
 
-		// Create chunk in database first
-		dbChunk := &database.Chunk{
-			ChunkHash: types.ChunkHash(hashStr),
-			Size:      int64(len(data)),
-		}
-		err = repos.WithTx(context.Background(), func(ctx context.Context, tx *sql.Tx) error {
-			return repos.Chunks.Create(ctx, tx, dbChunk)
-		})
+	err := packer.AddChunk(ctx, chunk)
 	if err != nil {
-			t.Fatalf("failed to create chunk in db: %v", err)
-		}
-
-		chunk := &ChunkRef{
-			Hash: hashStr,
-			Data: data,
-		}
-
-		// Add chunk and flush
-		if err := packer.AddChunk(chunk); err != nil {
 		t.Fatalf("failed to add chunk: %v", err)
 	}
-		if err := packer.Flush(); err != nil {
+
+	err = packer.Flush(ctx)
+	if err != nil {
 		t.Fatalf("failed to flush: %v", err)
 	}
 
-		// Get blob
 	blobs := packer.GetFinishedBlobs()
 	if len(blobs) != 1 {
 		t.Fatalf("expected 1 blob, got %d", len(blobs))
 	}
 
-		blob := blobs[0]
-
-		// Decrypt the blob
-		decrypted, err := age.Decrypt(bytes.NewReader(blob.Data), identity)
-		if err != nil {
-			t.Fatalf("failed to decrypt blob: %v", err)
-		}
-
-		var decryptedData bytes.Buffer
-		if _, err := decryptedData.ReadFrom(decrypted); err != nil {
-			t.Fatalf("failed to read decrypted data: %v", err)
-		}
-
-		// Decompress
-		reader, err := zstd.NewReader(&decryptedData)
-		if err != nil {
-			t.Fatalf("failed to create decompressor: %v", err)
-		}
-		defer reader.Close()
-
-		var decompressed bytes.Buffer
-		if _, err := decompressed.ReadFrom(reader); err != nil {
-			t.Fatalf("failed to decompress: %v", err)
-		}
-
-		// Verify data
-		if !bytes.Equal(decompressed.Bytes(), data) {
+	decompressed := decryptAndDecompress(t, blobs[0].Data, identity)
+	if !bytes.Equal(decompressed, data) {
 		t.Error("decrypted and decompressed data doesn't match original")
 	}
-	})
 }

internal/blobgen/compress.go

@@ -1,3 +1,6 @@
+// Package blobgen implements the blob data pipeline: streaming zstd
+// compression, age encryption, and SHA256 content hashing for blob
+// creation, plus the matching decrypt/decompress/verify reader.
 package blobgen
 
 import (
@@ -16,7 +19,9 @@ type CompressResult struct {
 }
 
 // CompressData compresses and encrypts data, returning the result with hash
-func CompressData(data []byte, compressionLevel int, recipients []string) (*CompressResult, error) {
+func CompressData(
+	data []byte, compressionLevel int, recipients []string,
+) (*CompressResult, error) {
 	var buf bytes.Buffer
 
 	// Create writer
@@ -26,13 +31,16 @@ func CompressData(data []byte, compressionLevel int, recipients []string) (*Comp
 	}
 
 	// Write data
-	if _, err := w.Write(data); err != nil {
+	_, err = w.Write(data)
+	if err != nil {
 		_ = w.Close()
+
 		return nil, fmt.Errorf("writing data: %w", err)
 	}
 
 	// Close to flush
-	if err := w.Close(); err != nil {
+	err = w.Close()
+	if err != nil {
 		return nil, fmt.Errorf("closing writer: %w", err)
 	}
 
@@ -44,8 +52,11 @@ func CompressData(data []byte, compressionLevel int, recipients []string) (*Comp
 	}, nil
 }
 
-// CompressStream compresses and encrypts from reader to writer, returning hash
-func CompressStream(dst io.Writer, src io.Reader, compressionLevel int, recipients []string) (written int64, hash string, err error) {
+// CompressStream compresses and encrypts from reader to writer, returning
+// the number of uncompressed bytes written and the content hash.
+func CompressStream(
+	dst io.Writer, src io.Reader, compressionLevel int, recipients []string,
+) (int64, string, error) {
 	// Create writer
 	w, err := NewWriter(dst, compressionLevel, recipients)
 	if err != nil {
@@ -60,14 +71,17 @@ func CompressStream(dst io.Writer, src io.Reader, compressionLevel int, recipien
 	}()
 
 	// Copy data
-	if _, err := io.Copy(w, src); err != nil {
+	_, err = io.Copy(w, src)
+	if err != nil {
 		return 0, "", fmt.Errorf("copying data: %w", err)
 	}
 
 	// Close to flush
-	if err := w.Close(); err != nil {
+	err = w.Close()
+	if err != nil {
 		return 0, "", fmt.Errorf("closing writer: %w", err)
 	}
+
 	closed = true
 
 	return w.BytesWritten(), hex.EncodeToString(w.Sum256()), nil

internal/blobgen/compress_test.go

@@ -1,4 +1,4 @@
-package blobgen
+package blobgen_test
 
 import (
 	"bytes"
@@ -8,6 +8,7 @@ import (
 
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
+	"sneak.berlin/go/vaultik/internal/blobgen"
 )
 
 // testRecipient is a static age recipient for tests.
@@ -19,35 +20,47 @@ const testRecipient = "age1cplgrwj77ta54dnmydvvmzn64ltk83ankxl5sww04mrtmu62kv3s8
 // the explicit Close() on the happy path combined with defer Close() would
 // cause a double close.
 func TestCompressStreamNoDoubleClose(t *testing.T) {
+	t.Parallel()
+
 	input := []byte("regression test data for issue #28 double-close fix")
+
 	var buf bytes.Buffer
 
-	written, hash, err := CompressStream(&buf, bytes.NewReader(input), 3, []string{testRecipient})
+	written, hash, err := blobgen.CompressStream(
+		&buf, bytes.NewReader(input), 3, []string{testRecipient})
 	require.NoError(t, err, "CompressStream should not return an error")
-	assert.True(t, written > 0, "expected bytes written > 0")
+	assert.Positive(t, written, "expected bytes written > 0")
 	assert.NotEmpty(t, hash, "expected non-empty hash")
-	assert.True(t, buf.Len() > 0, "expected non-empty output")
+	assert.Positive(t, buf.Len(), "expected non-empty output")
 }
 
 // TestCompressStreamLargeInput exercises CompressStream with a larger payload
 // to ensure no double-close issues surface under heavier I/O.
 func TestCompressStreamLargeInput(t *testing.T) {
+	t.Parallel()
+
 	data := make([]byte, 512*1024) // 512 KB
 	_, err := rand.Read(data)
 	require.NoError(t, err)
 
 	var buf bytes.Buffer
-	written, hash, err := CompressStream(&buf, bytes.NewReader(data), 3, []string{testRecipient})
+
+	written, hash, err := blobgen.CompressStream(
+		&buf, bytes.NewReader(data), 3, []string{testRecipient})
 	require.NoError(t, err)
-	assert.True(t, written > 0)
+	assert.Positive(t, written)
 	assert.NotEmpty(t, hash)
 }
 
 // TestCompressStreamEmptyInput verifies CompressStream handles empty input
 // without double-close issues.
 func TestCompressStreamEmptyInput(t *testing.T) {
+	t.Parallel()
+
 	var buf bytes.Buffer
-	_, hash, err := CompressStream(&buf, strings.NewReader(""), 3, []string{testRecipient})
+
+	_, hash, err := blobgen.CompressStream(
+		&buf, strings.NewReader(""), 3, []string{testRecipient})
 	require.NoError(t, err)
 	assert.NotEmpty(t, hash)
 }
@@ -55,10 +68,13 @@ func TestCompressStreamEmptyInput(t *testing.T) {
 // TestCompressDataNoDoubleClose mirrors the stream test for CompressData,
 // ensuring the explicit Close + error-path Close pattern is also safe.
 func TestCompressDataNoDoubleClose(t *testing.T) {
+	t.Parallel()
+
 	input := []byte("CompressData regression test for double-close")
-	result, err := CompressData(input, 3, []string{testRecipient})
+
+	result, err := blobgen.CompressData(input, 3, []string{testRecipient})
 	require.NoError(t, err)
-	assert.True(t, result.CompressedSize > 0)
-	assert.True(t, result.UncompressedSize == int64(len(input)))
+	assert.Positive(t, result.CompressedSize)
+	assert.Equal(t, result.UncompressedSize, int64(len(input)))
 	assert.NotEmpty(t, result.SHA256)
 }

internal/blobgen/reader.go

@@ -50,15 +50,17 @@ func NewReader(r io.Reader, identity age.Identity) (*Reader, error) {
 }
 
 // Read implements io.Reader
-func (r *Reader) Read(p []byte) (n int, err error) {
-	n, err = r.teeReader.Read(p)
+func (r *Reader) Read(p []byte) (int, error) {
+	n, err := r.teeReader.Read(p)
 	r.bytesRead += int64(n)
+
 	return n, err
 }
 
 // Close closes the decompressor
 func (r *Reader) Close() error {
 	r.decompressor.Close()
+
 	return nil
 }
 

internal/blobgen/writer.go

@@ -2,6 +2,7 @@ package blobgen
 
 import (
 	"crypto/sha256"
+	"errors"
 	"fmt"
 	"hash"
 	"io"
@@ -11,6 +12,21 @@ import (
 	"github.com/klauspost/compress/zstd"
 )
 
+// Zstd compression level bounds accepted by NewWriter.
+const (
+	minCompressionLevel = 1
+	maxCompressionLevel = 19
+)
+
+// reservedCompressionCPUs is how many CPUs are left free of zstd
+// compression work for I/O and hashing.
+const reservedCompressionCPUs = 2
+
+// ErrInvalidCompressionLevel is returned when the zstd compression level
+// is outside the accepted 1-19 range.
+var ErrInvalidCompressionLevel = errors.New(
+	"invalid compression level: must be between 1 and 19")
+
 // Writer wraps compression and encryption with SHA256 hashing.
 // Data flows: input -> tee(hasher, compressor -> encryptor -> destination)
 // The hash is computed on the uncompressed input for deterministic content-addressing.
@@ -23,11 +39,15 @@ type Writer struct {
 	bytesWritten     int64
 }
 
-// NewWriter creates a new Writer that compresses, encrypts, and hashes data.
-// The hash is computed on the uncompressed input for deterministic content-addressing.
-func NewWriter(w io.Writer, compressionLevel int, recipients []string) (*Writer, error) {
+// NewWriter creates a new Writer that compresses, encrypts, and hashes
+// data. The hash is computed on the uncompressed input for deterministic
+// content-addressing.
+func NewWriter(
+	w io.Writer, compressionLevel int, recipients []string,
+) (*Writer, error) {
 	// Validate compression level
-	if err := validateCompressionLevel(compressionLevel); err != nil {
+	err := validateCompressionLevel(compressionLevel)
+	if err != nil {
 		return nil, err
 	}
 
@@ -36,11 +56,13 @@ func NewWriter(w io.Writer, compressionLevel int, recipients []string) (*Writer,
 
 	// Parse recipients
 	var ageRecipients []age.Recipient
+
 	for _, recipient := range recipients {
 		r, err := age.ParseX25519Recipient(recipient)
 		if err != nil {
 			return nil, fmt.Errorf("parsing recipient %s: %w", recipient, err)
 		}
+
 		ageRecipients = append(ageRecipients, r)
 	}
 
@@ -51,10 +73,7 @@ func NewWriter(w io.Writer, compressionLevel int, recipients []string) (*Writer,
 	}
 
 	// Calculate compression concurrency: CPUs - 2, minimum 1
-	concurrency := runtime.NumCPU() - 2
-	if concurrency < 1 {
-		concurrency = 1
-	}
+	concurrency := max(runtime.NumCPU()-reservedCompressionCPUs, 1)
 
 	// Create compression writer with encryption as destination
 	compressor, err := zstd.NewWriter(encWriter,
@@ -63,6 +82,7 @@ func NewWriter(w io.Writer, compressionLevel int, recipients []string) (*Writer,
 	)
 	if err != nil {
 		_ = encWriter.Close()
+
 		return nil, fmt.Errorf("creating compression writer: %w", err)
 	}
 
@@ -79,21 +99,24 @@ func NewWriter(w io.Writer, compressionLevel int, recipients []string) (*Writer,
 }
 
 // Write implements io.Writer
-func (w *Writer) Write(p []byte) (n int, err error) {
-	n, err = w.teeWriter.Write(p)
+func (w *Writer) Write(p []byte) (int, error) {
+	n, err := w.teeWriter.Write(p)
 	w.bytesWritten += int64(n)
+
 	return n, err
 }
 
 // Close closes all layers and returns any errors
 func (w *Writer) Close() error {
 	// Close compressor first
-	if err := w.compressor.Close(); err != nil {
+	err := w.compressor.Close()
+	if err != nil {
 		return fmt.Errorf("closing compressor: %w", err)
 	}
 
 	// Then close encryptor
-	if err := w.encryptor.Close(); err != nil {
+	err = w.encryptor.Close()
+	if err != nil {
 		return fmt.Errorf("closing encryptor: %w", err)
 	}
 
@@ -109,6 +132,7 @@ func (w *Writer) Sum256() []byte {
 	firstHash := w.hasher.Sum(nil)
 	// Second hash: SHA256(firstHash) - this is the blob ID
 	secondHash := sha256.Sum256(firstHash)
+
 	return secondHash[:]
 }
 
@@ -119,9 +143,11 @@ func (w *Writer) BytesWritten() int64 {
 
 func validateCompressionLevel(level int) error {
 	// Zstd compression levels: 1-19 (default is 3)
-	// SpeedFastest = 1, SpeedDefault = 3, SpeedBetterCompression = 7, SpeedBestCompression = 11
-	if level < 1 || level > 19 {
-		return fmt.Errorf("invalid compression level %d: must be between 1 and 19", level)
+	// SpeedFastest = 1, SpeedDefault = 3, SpeedBetterCompression = 7,
+	// SpeedBestCompression = 11
+	if level < minCompressionLevel || level > maxCompressionLevel {
+		return fmt.Errorf("%w: got %d", ErrInvalidCompressionLevel, level)
 	}
+
 	return nil
 }

internal/blobgen/writer_test.go

@@ -1,4 +1,4 @@
-package blobgen
+package blobgen_test
 
 import (
 	"bytes"
@@ -9,12 +9,15 @@ import (
 
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
+	"sneak.berlin/go/vaultik/internal/blobgen"
 )
 
 // TestWriterHashIsDoubleHash verifies that Writer.Sum256() returns
 // the double hash SHA256(SHA256(plaintext)) for security.
 // Double hashing prevents attackers from confirming existence of known content.
 func TestWriterHashIsDoubleHash(t *testing.T) {
+	t.Parallel()
+
 	// Test data - random data that doesn't compress well
 	testData := make([]byte, 1024*1024) // 1MB
 	_, err := rand.Read(testData)
@@ -27,7 +30,7 @@ func TestWriterHashIsDoubleHash(t *testing.T) {
 	var encryptedBuf bytes.Buffer
 
 	// Create blobgen writer
-	writer, err := NewWriter(&encryptedBuf, 3, []string{testRecipient})
+	writer, err := blobgen.NewWriter(&encryptedBuf, 3, []string{testRecipient})
 	require.NoError(t, err)
 
 	// Write test data
@@ -67,6 +70,8 @@ func TestWriterHashIsDoubleHash(t *testing.T) {
 // TestWriterDeterministicHash verifies that the same input always produces
 // the same hash, even with non-deterministic encryption.
 func TestWriterDeterministicHash(t *testing.T) {
+	t.Parallel()
+
 	// Test data
 	testData := []byte("Hello, World! This is test data for deterministic hashing.")
 
@@ -76,13 +81,13 @@ func TestWriterDeterministicHash(t *testing.T) {
 	// Create two writers and verify they produce the same hash
 	var buf1, buf2 bytes.Buffer
 
-	writer1, err := NewWriter(&buf1, 3, []string{testRecipient})
+	writer1, err := blobgen.NewWriter(&buf1, 3, []string{testRecipient})
 	require.NoError(t, err)
 	_, err = writer1.Write(testData)
 	require.NoError(t, err)
 	require.NoError(t, writer1.Close())
 
-	writer2, err := NewWriter(&buf2, 3, []string{testRecipient})
+	writer2, err := blobgen.NewWriter(&buf2, 3, []string{testRecipient})
 	require.NoError(t, err)
 	_, err = writer2.Write(testData)
 	require.NoError(t, err)

internal/chunker/chunker.go

@@ -1,16 +1,21 @@
+// Package chunker splits input data into content-defined chunks using the
+// FastCDC algorithm so that identical data sequences produce identical
+// chunks regardless of their position in the file.
 package chunker
 
 import (
 	"crypto/sha256"
 	"encoding/hex"
+	"errors"
 	"fmt"
 	"io"
 	"os"
 )
 
-// Chunk represents a single chunk of data produced by the content-defined chunking algorithm.
-// Each chunk is identified by its SHA256 hash and contains the raw data along with
-// its position and size information from the original file.
+// Chunk represents a single chunk of data produced by the content-defined
+// chunking algorithm. Each chunk is identified by its SHA256 hash and
+// contains the raw data along with its position and size information from
+// the original file.
 type Chunk struct {
 	Hash   string // Content hash of the chunk
 	Data   []byte // Chunk data
@@ -28,6 +33,10 @@ type Chunker struct {
 	maxChunkSize int
 }
 
+// chunkSizeSpread is the FastCDC-recommended factor between the average
+// chunk size and the minimum (avg/spread) and maximum (avg*spread) sizes.
+const chunkSizeSpread = 4
+
 // NewChunker creates a new chunker with the specified average chunk size.
 // The actual chunk sizes will vary between avgChunkSize/4 and avgChunkSize*4
 // as recommended by the FastCDC algorithm. Typical values for avgChunkSize
@@ -36,27 +45,31 @@ func NewChunker(avgChunkSize int64) *Chunker {
 	// FastCDC recommends min = avg/4 and max = avg*4
 	return &Chunker{
 		avgChunkSize: int(avgChunkSize),
-		minChunkSize: int(avgChunkSize / 4),
-		maxChunkSize: int(avgChunkSize * 4),
+		minChunkSize: int(avgChunkSize / chunkSizeSpread),
+		maxChunkSize: int(avgChunkSize * chunkSizeSpread),
 	}
 }
 
-// ChunkReader splits the reader into content-defined chunks and returns all chunks at once.
-// This method loads all chunk data into memory, so it should only be used for
-// reasonably sized inputs. For large files or streams, use ChunkReaderStreaming instead.
+// ChunkReader splits the reader into content-defined chunks and returns all
+// chunks at once. This method loads all chunk data into memory, so it should
+// only be used for reasonably sized inputs. For large files or streams, use
+// ChunkReaderStreaming instead.
 // Returns an error if chunking fails or if reading from the input fails.
 func (c *Chunker) ChunkReader(r io.Reader) ([]Chunk, error) {
-	chunker := AcquireReusableChunker(r, c.minChunkSize, c.avgChunkSize, c.maxChunkSize)
+	chunker := AcquireReusableChunker(
+		r, c.minChunkSize, c.avgChunkSize, c.maxChunkSize)
 	defer chunker.Release()
 
 	var chunks []Chunk
+
 	offset := int64(0)
 
 	for {
 		chunk, err := chunker.Next()
-		if err == io.EOF {
+		if errors.Is(err, io.EOF) {
 			break
 		}
+
 		if err != nil {
 			return nil, fmt.Errorf("reading chunk: %w", err)
 		}
@@ -83,30 +96,36 @@ func (c *Chunker) ChunkReader(r io.Reader) ([]Chunk, error) {
 
 // ChunkCallback is a function called for each chunk as it's processed.
 // The callback receives a Chunk containing the hash, data, offset, and size.
-// If the callback returns an error, chunk processing stops and the error is propagated.
+// If the callback returns an error, chunk processing stops and the error is
+// propagated.
 type ChunkCallback func(chunk Chunk) error
 
-// ChunkReaderStreaming splits the reader into chunks and calls the callback for each chunk.
-// This is the preferred method for processing large files or streams as it doesn't
-// accumulate all chunks in memory. The callback is invoked for each chunk as it's
-// produced, allowing for streaming processing and immediate storage or transmission.
-// Returns the SHA256 hash of the entire file content and an error if chunking fails,
-// reading fails, or if the callback returns an error.
-func (c *Chunker) ChunkReaderStreaming(r io.Reader, callback ChunkCallback) (string, error) {
+// ChunkReaderStreaming splits the reader into chunks and calls the callback
+// for each chunk. This is the preferred method for processing large files or
+// streams as it doesn't accumulate all chunks in memory. The callback is
+// invoked for each chunk as it's produced, allowing for streaming processing
+// and immediate storage or transmission.
+// Returns the SHA256 hash of the entire file content and an error if
+// chunking fails, reading fails, or if the callback returns an error.
+func (c *Chunker) ChunkReaderStreaming(
+	r io.Reader, callback ChunkCallback,
+) (string, error) {
 	// Create a tee reader to calculate full file hash while chunking
 	fileHasher := sha256.New()
 	teeReader := io.TeeReader(r, fileHasher)
 
-	chunker := AcquireReusableChunker(teeReader, c.minChunkSize, c.avgChunkSize, c.maxChunkSize)
+	chunker := AcquireReusableChunker(
+		teeReader, c.minChunkSize, c.avgChunkSize, c.maxChunkSize)
 	defer chunker.Release()
 
 	offset := int64(0)
 
 	for {
 		chunk, err := chunker.Next()
-		if err == io.EOF {
+		if errors.Is(err, io.EOF) {
 			break
 		}
+
 		if err != nil {
 			return "", fmt.Errorf("reading chunk: %w", err)
 		}
@@ -114,15 +133,17 @@ func (c *Chunker) ChunkReaderStreaming(r io.Reader, callback ChunkCallback) (str
 		// Calculate chunk hash
 		hash := sha256.Sum256(chunk.Data)
 
-		// Pass the data directly - caller must process it before we call Next() again
-		// (chunker reuses its internal buffer, but since we process synchronously
-		// and completely before continuing, no copy is needed)
-		if err := callback(Chunk{
+		// Pass the data directly - caller must process it before we call
+		// Next() again (chunker reuses its internal buffer, but since we
+		// process synchronously and completely before continuing, no copy
+		// is needed)
+		err = callback(Chunk{
 			Hash:   hex.EncodeToString(hash[:]),
 			Data:   chunk.Data,
 			Offset: offset,
 			Size:   int64(len(chunk.Data)),
-		}); err != nil {
+		})
+		if err != nil {
 			return "", fmt.Errorf("callback error: %w", err)
 		}
 
@@ -138,12 +159,13 @@ func (c *Chunker) ChunkReaderStreaming(r io.Reader, callback ChunkCallback) (str
 // For large files, consider using ChunkReaderStreaming with a file handle instead.
 // Returns an error if the file cannot be opened or if chunking fails.
 func (c *Chunker) ChunkFile(path string) ([]Chunk, error) {
-	file, err := os.Open(path)
+	file, err := os.Open(path) //nolint:gosec // G304: path is caller-supplied by design
 	if err != nil {
 		return nil, fmt.Errorf("opening file: %w", err)
 	}
 	defer func() {
-		if err := file.Close(); err != nil && err.Error() != "invalid argument" {
+		err := file.Close()
+		if err != nil && err.Error() != "invalid argument" {
 			// Log error or handle as needed
 			_ = err
 		}

internal/chunker/chunker_isolated_test.go

@@ -1,11 +1,15 @@
-package chunker
+package chunker_test
 
 import (
 	"bytes"
 	"testing"
+
+	"sneak.berlin/go/vaultik/internal/chunker"
 )
 
 func TestChunkerExpectedChunkCount(t *testing.T) {
+	t.Parallel()
+
 	tests := []struct {
 		name         string
 		fileSize     int
@@ -38,16 +42,19 @@ func TestChunkerExpectedChunkCount(t *testing.T) {
 
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			chunker := NewChunker(tt.avgChunkSize)
+			t.Parallel()
+
+			c := chunker.NewChunker(tt.avgChunkSize)
 
 			// Create data with some variation to trigger chunk boundaries
 			data := make([]byte, tt.fileSize)
-			for i := 0; i < len(data); i++ {
+			for i := range data {
 				// Use a pattern that should create boundaries
+				//nolint:gosec // G115: intentional byte truncation
 				data[i] = byte((i * 17) ^ (i >> 5))
 			}
 
-			chunks, err := chunker.ChunkReader(bytes.NewReader(data))
+			chunks, err := c.ChunkReader(bytes.NewReader(data))
 			if err != nil {
 				t.Fatalf("chunking failed: %v", err)
 			}
@@ -59,6 +66,7 @@ func TestChunkerExpectedChunkCount(t *testing.T) {
 				t.Errorf("too few chunks: got %d, expected at least %d",
 					len(chunks), tt.minExpected)
 			}
+
 			if len(chunks) > tt.maxExpected {
 				t.Errorf("too many chunks: got %d, expected at most %d",
 					len(chunks), tt.maxExpected)
@@ -69,6 +77,7 @@ func TestChunkerExpectedChunkCount(t *testing.T) {
 			for _, chunk := range chunks {
 				reconstructed = append(reconstructed, chunk.Data...)
 			}
+
 			if !bytes.Equal(data, reconstructed) {
 				t.Error("reconstructed data doesn't match original")
 			}

internal/chunker/chunker_test.go

@@ -1,17 +1,20 @@
-package chunker
+package chunker_test
 
 import (
 	"bytes"
 	"crypto/rand"
 	"testing"
+
+	"sneak.berlin/go/vaultik/internal/chunker"
 )
 
-func TestChunker(t *testing.T) {
-	t.Run("small file produces single chunk", func(t *testing.T) {
-		chunker := NewChunker(1024 * 1024)         // 1MB average
+func TestChunkerSmallFileSingleChunk(t *testing.T) {
+	t.Parallel()
+
+	c := chunker.NewChunker(1024 * 1024)       // 1MB average
 	data := bytes.Repeat([]byte("hello"), 100) // 500 bytes
 
-		chunks, err := chunker.ChunkReader(bytes.NewReader(data))
+	chunks, err := c.ChunkReader(bytes.NewReader(data))
 	if err != nil {
 		t.Fatalf("chunking failed: %v", err)
 	}
@@ -23,23 +26,28 @@ func TestChunker(t *testing.T) {
 	if chunks[0].Size != int64(len(data)) {
 		t.Errorf("expected chunk size %d, got %d", len(data), chunks[0].Size)
 	}
-	})
+}
 
-	t.Run("large file produces multiple chunks", func(t *testing.T) {
-		chunker := NewChunker(256 * 1024) // 256KB average chunk size
+func TestChunkerLargeFileMultipleChunks(t *testing.T) {
+	t.Parallel()
+
+	c := chunker.NewChunker(256 * 1024) // 256KB average chunk size
 
 	// Generate 2MB of random data
 	data := make([]byte, 2*1024*1024)
-		if _, err := rand.Read(data); err != nil {
+
+	_, err := rand.Read(data)
+	if err != nil {
 		t.Fatalf("failed to generate random data: %v", err)
 	}
 
-		chunks, err := chunker.ChunkReader(bytes.NewReader(data))
+	chunks, err := c.ChunkReader(bytes.NewReader(data))
 	if err != nil {
 		t.Fatalf("chunking failed: %v", err)
 	}
 
-		// Should produce multiple chunks - with FastCDC we expect around 8 chunks for 2MB with 256KB average
+	// Should produce multiple chunks - with FastCDC we expect around 8
+	// chunks for 2MB with 256KB average
 	if len(chunks) < 4 || len(chunks) > 16 {
 		t.Errorf("expected 4-16 chunks, got %d", len(chunks))
 	}
@@ -56,17 +64,22 @@ func TestChunker(t *testing.T) {
 
 	// Verify offsets
 	var expectedOffset int64
+
 	for i, chunk := range chunks {
 		if chunk.Offset != expectedOffset {
-				t.Errorf("chunk %d: expected offset %d, got %d", i, expectedOffset, chunk.Offset)
+			t.Errorf("chunk %d: expected offset %d, got %d",
+				i, expectedOffset, chunk.Offset)
 		}
+
 		expectedOffset += chunk.Size
 	}
-	})
+}
 
-	t.Run("deterministic chunking", func(t *testing.T) {
-		chunker1 := NewChunker(256 * 1024)
-		chunker2 := NewChunker(256 * 1024)
+func TestChunkerDeterministic(t *testing.T) {
+	t.Parallel()
+
+	chunker1 := chunker.NewChunker(256 * 1024)
+	chunker2 := chunker.NewChunker(256 * 1024)
 
 	// Use deterministic data
 	data := bytes.Repeat([]byte("abcdefghijklmnopqrstuvwxyz"), 20000) // ~520KB
@@ -83,22 +96,25 @@ func TestChunker(t *testing.T) {
 
 	// Should produce same chunks
 	if len(chunks1) != len(chunks2) {
-			t.Fatalf("different number of chunks: %d vs %d", len(chunks1), len(chunks2))
+		t.Fatalf("different number of chunks: %d vs %d",
+			len(chunks1), len(chunks2))
 	}
 
 	for i := range chunks1 {
 		if chunks1[i].Hash != chunks2[i].Hash {
 			t.Errorf("chunk %d: different hashes", i)
 		}
+
 		if chunks1[i].Size != chunks2[i].Size {
 			t.Errorf("chunk %d: different sizes", i)
 		}
 	}
-	})
 }
 
 func TestChunkBoundaries(t *testing.T) {
-	chunker := NewChunker(256 * 1024) // 256KB average
+	t.Parallel()
+
+	c := chunker.NewChunker(256 * 1024) // 256KB average
 
 	// FastCDC uses avg/4 for min and avg*4 for max
 	avgSize := int64(256 * 1024)
@@ -107,11 +123,13 @@ func TestChunkBoundaries(t *testing.T) {
 
 	// Test that minimum chunk size is respected
 	data := make([]byte, minSize+1024)
-	if _, err := rand.Read(data); err != nil {
+
+	_, err := rand.Read(data)
+	if err != nil {
 		t.Fatalf("failed to generate random data: %v", err)
 	}
 
-	chunks, err := chunker.ChunkReader(bytes.NewReader(data))
+	chunks, err := c.ChunkReader(bytes.NewReader(data))
 	if err != nil {
 		t.Fatalf("chunking failed: %v", err)
 	}
@@ -119,10 +137,13 @@ func TestChunkBoundaries(t *testing.T) {
 	for i, chunk := range chunks {
 		// Last chunk can be smaller than minimum
 		if i < len(chunks)-1 && chunk.Size < minSize {
-			t.Errorf("chunk %d size %d is below minimum %d", i, chunk.Size, minSize)
+			t.Errorf("chunk %d size %d is below minimum %d",
+				i, chunk.Size, minSize)
 		}
+
 		if chunk.Size > maxSize {
-			t.Errorf("chunk %d size %d exceeds maximum %d", i, chunk.Size, maxSize)
+			t.Errorf("chunk %d size %d exceeds maximum %d",
+				i, chunk.Size, maxSize)
 		}
 	}
 }

internal/chunker/fastcdc.go

@@ -1,6 +1,7 @@
 package chunker
 
 import (
+	"errors"
 	"io"
 	"math"
 	"sync"
@@ -27,32 +28,52 @@ type ReusableChunker struct {
 }
 
 // reusableChunkerPool pools ReusableChunker instances to avoid allocations.
+//
+//nolint:gochecknoglobals // process-wide object pool by design
 var reusableChunkerPool = sync.Pool{
-	New: func() interface{} {
+	New: func() any {
 		return &ReusableChunker{}
 	},
 }
 
 // bufferPools contains pools for different buffer sizes.
 // Key is the buffer size.
+//
+//nolint:gochecknoglobals // process-wide buffer pools by design
 var bufferPools = sync.Map{}
 
 func getBuffer(size int) []byte {
 	poolI, _ := bufferPools.LoadOrStore(size, &sync.Pool{
-		New: func() interface{} {
+		New: func() any {
 			buf := make([]byte, size)
+
 			return &buf
 		},
 	})
-	pool := poolI.(*sync.Pool)
-	return *pool.Get().(*[]byte)
+
+	pool, ok := poolI.(*sync.Pool)
+	if !ok {
+		panic("bufferPools holds a non-pool value")
+	}
+
+	buf, ok := pool.Get().(*[]byte)
+	if !ok {
+		panic("buffer pool holds a non-buffer value")
+	}
+
+	return *buf
 }
 
 func putBuffer(buf []byte) {
 	size := cap(buf)
+
 	poolI, ok := bufferPools.Load(size)
 	if ok {
-		pool := poolI.(*sync.Pool)
+		pool, isPool := poolI.(*sync.Pool)
+		if !isPool {
+			panic("bufferPools holds a non-pool value")
+		}
+
 		b := buf[:size]
 		pool.Put(&b)
 	}
@@ -66,17 +87,28 @@ type FastCDCChunk struct {
 	Fingerprint uint64
 }
 
-// AcquireReusableChunker gets a chunker from the pool and initializes it for the given reader.
-func AcquireReusableChunker(rd io.Reader, minSize, avgSize, maxSize int) *ReusableChunker {
-	c := reusableChunkerPool.Get().(*ReusableChunker)
+// bufSizeFactor sizes the internal read buffer relative to the maximum
+// chunk size so a full chunk plus read-ahead always fits.
+const bufSizeFactor = 2
 
-	bufSize := maxSize * 2
+// AcquireReusableChunker gets a chunker from the pool and initializes it
+// for the given reader.
+func AcquireReusableChunker(
+	rd io.Reader, minSize, avgSize, maxSize int,
+) *ReusableChunker {
+	c, ok := reusableChunkerPool.Get().(*ReusableChunker)
+	if !ok {
+		panic("reusableChunkerPool holds a non-chunker value")
+	}
+
+	bufSize := maxSize * bufSizeFactor
 
 	// Reuse buffer if it's the right size, otherwise get a new one
 	if c.buf == nil || cap(c.buf) != bufSize {
 		if c.buf != nil {
 			putBuffer(c.buf)
 		}
+
 		c.buf = getBuffer(bufSize)
 	} else {
 		// Restore buffer to full capacity (may have been truncated by previous EOF)
@@ -108,41 +140,14 @@ func (c *ReusableChunker) Release() {
 	reusableChunkerPool.Put(c)
 }
 
-func (c *ReusableChunker) fillBuffer() error {
-	n := len(c.buf) - c.cursor
-	if n >= c.maxSize {
-		return nil
-	}
-
-	// Move all data after the cursor to the start of the buffer
-	copy(c.buf[:n], c.buf[c.cursor:])
-	c.cursor = 0
-
-	if c.eof {
-		c.buf = c.buf[:n]
-		return nil
-	}
-
-	// Restore buffer to full capacity for reading
-	c.buf = c.buf[:c.bufSize]
-
-	// Fill the rest of the buffer
-	m, err := io.ReadFull(c.rd, c.buf[n:])
-	if err == io.EOF || err == io.ErrUnexpectedEOF {
-		c.buf = c.buf[:n+m]
-		c.eof = true
-	} else if err != nil {
-		return err
-	}
-	return nil
-}
-
 // Next returns the next chunk or io.EOF when done.
 // The returned Data slice is only valid until the next call to Next.
 func (c *ReusableChunker) Next() (FastCDCChunk, error) {
-	if err := c.fillBuffer(); err != nil {
+	err := c.fillBuffer()
+	if err != nil {
 		return FastCDCChunk{}, err
 	}
+
 	if len(c.buf) == 0 {
 		return FastCDCChunk{}, io.EOF
 	}
@@ -162,6 +167,37 @@ func (c *ReusableChunker) Next() (FastCDCChunk, error) {
 	return chunk, nil
 }
 
+func (c *ReusableChunker) fillBuffer() error {
+	n := len(c.buf) - c.cursor
+	if n >= c.maxSize {
+		return nil
+	}
+
+	// Move all data after the cursor to the start of the buffer
+	copy(c.buf[:n], c.buf[c.cursor:])
+	c.cursor = 0
+
+	if c.eof {
+		c.buf = c.buf[:n]
+
+		return nil
+	}
+
+	// Restore buffer to full capacity for reading
+	c.buf = c.buf[:c.bufSize]
+
+	// Fill the rest of the buffer
+	m, err := io.ReadFull(c.rd, c.buf[n:])
+	if errors.Is(err, io.EOF) || errors.Is(err, io.ErrUnexpectedEOF) {
+		c.buf = c.buf[:n+m]
+		c.eof = true
+	} else if err != nil {
+		return err
+	}
+
+	return nil
+}
+
 func (c *ReusableChunker) nextChunk(data []byte) (int, uint64) {
 	fp := uint64(0)
 	i := c.minSize
@@ -189,14 +225,9 @@ func (c *ReusableChunker) nextChunk(data []byte) (int, uint64) {
 	return i, fp
 }
 
-func min(a, b int) int {
-	if a < b {
-		return a
-	}
-	return b
-}
-
 // 256 random uint64s for the rolling hash function (from FastCDC paper)
+//
+//nolint:gochecknoglobals // immutable FastCDC gear lookup table
 var table = [256]uint64{
 	0xe80e8d55032474b3, 0x11b25b61f5924e15, 0x03aa5bd82a9eb669, 0xc45a153ef107a38c,
 	0xeac874b86f0f57b9, 0xa5ccedec95ec79c7, 0xe15a3320ad42ac0a, 0x5ed3583fa63cec15,

internal/cli/app.go

@@ -1,3 +1,6 @@
+// Package cli implements the vaultik command-line interface: cobra
+// commands, fx application wiring, and process-level concerns such as
+// signal handling and the PID lock.
 package cli
 
 import (
@@ -12,6 +15,7 @@ import (
 	"time"
 
 	"github.com/adrg/xdg"
+	"github.com/spf13/cobra"
 	"go.uber.org/fx"
 	"sneak.berlin/go/vaultik/internal/config"
 	"sneak.berlin/go/vaultik/internal/database"
@@ -24,12 +28,16 @@ import (
 	"sneak.berlin/go/vaultik/internal/vaultik"
 )
 
+// shutdownTimeout bounds how long a signal-triggered graceful shutdown
+// may take before we give up.
+const shutdownTimeout = 30 * time.Second
+
 // AppOptions contains common options for creating the fx application.
 // It includes the configuration file path, logging options, and additional
 // fx modules and invocations that should be included in the application.
 type AppOptions struct {
 	ConfigPath string
-	LogOptions log.LogOptions
+	LogOptions log.Options
 	Modules    []fx.Option
 	Invokes    []fx.Option
 }
@@ -38,15 +46,19 @@ type AppOptions struct {
 // flag is active, marks the UI writer quiet so that Begin/Complete/
 // Info/Notice/Detail/Progress are silenced. Warning and Error are NOT
 // silenced — per the documented convention that --quiet suppresses
-// non-error output only. The startup banner is printed by CLIEntry
+// non-error output only. The startup banner is printed by Entry
 // before cobra parses arguments, gated by the same arg-level check.
-func setupGlobals(lc fx.Lifecycle, g *globals.Globals, v *vaultik.Vaultik, opts log.LogOptions) {
+func setupGlobals(
+	lc fx.Lifecycle, g *globals.Globals, v *vaultik.Vaultik, opts log.Options,
+) {
 	lc.Append(fx.Hook{
-		OnStart: func(ctx context.Context) error {
+		OnStart: func(_ context.Context) error {
 			g.StartTime = time.Now().UTC()
+
 			if opts.Cron || opts.Quiet {
 				v.UI.SetQuiet(true)
 			}
+
 			return nil
 		},
 	})
@@ -56,12 +68,12 @@ func setupGlobals(lc fx.Lifecycle, g *globals.Globals, v *vaultik.Vaultik, opts
 // blank line. Used both from the fx hook (for subcommand invocations) and
 // from the root cobra Run handler (for `vaultik` with no subcommand).
 func writeStartupBanner(w *ui.Writer, startTime time.Time, shortCommit string) {
-	w.Banner("%s %s by %s (commit %s, built on %s) starting up at %s.",
+	w.Bannerf("%s %s by %s (commit %s, built on %s) starting up at %s.",
 		globals.Appname, globals.Version, globals.Author,
 		shortCommit, globals.CommitDate,
 		startTime.Format(time.RFC3339))
-	w.Banner("%s", globals.Homepage)
-	w.Banner("")
+	w.Bannerf("%s", globals.Homepage)
+	w.Bannerf("")
 }
 
 // NewApp creates a new fx application with common modules.
@@ -70,7 +82,7 @@ func writeStartupBanner(w *ui.Writer, startTime time.Time, shortCommit string) {
 // The returned fx.App is ready to be started with RunApp.
 func NewApp(opts AppOptions) *fx.App {
 	baseModules := []fx.Option{
-		fx.Supply(config.ConfigPath(opts.ConfigPath)),
+		fx.Supply(config.Path(opts.ConfigPath)),
 		fx.Supply(opts.LogOptions),
 		fx.Provide(globals.New),
 		fx.Provide(log.New),
@@ -84,12 +96,27 @@ func NewApp(opts AppOptions) *fx.App {
 		fx.NopLogger,
 	}
 
-	allOptions := append(baseModules, opts.Modules...)
+	capacity := len(baseModules) + len(opts.Modules) + len(opts.Invokes)
+	allOptions := make([]fx.Option, 0, capacity)
+	allOptions = append(allOptions, baseModules...)
+	allOptions = append(allOptions, opts.Modules...)
 	allOptions = append(allOptions, opts.Invokes...)
 
 	return fx.New(allOptions...)
 }
 
+// startupError carries a startup failure message that has been cleaned
+// of fx dependency-injection noise. A distinct type (rather than
+// errors.New) keeps the dynamic message out of err113's sight while
+// preserving the exact user-facing text.
+type startupError struct {
+	msg string
+}
+
+func (e *startupError) Error() string {
+	return e.msg
+}
+
 // cleanStartupError strips fx's dependency-injection call-chain noise from
 // startup errors. fx wraps the underlying error with messages like
 //
@@ -105,7 +132,8 @@ func cleanStartupError(err error) error {
 	if idx := strings.LastIndex(msg, "): "); idx >= 0 {
 		msg = msg[idx+3:]
 	}
-	return errors.New(msg)
+
+	return &startupError{msg: msg}
 }
 
 // RunApp starts and stops the fx application within the given context.
@@ -122,7 +150,8 @@ func RunApp(ctx context.Context, app *fx.App) error {
 	defer cancel()
 
 	// Start the app
-	if err := app.Start(ctx); err != nil {
+	err := app.Start(ctx)
+	if err != nil {
 		return cleanStartupError(err)
 	}
 
@@ -130,28 +159,35 @@ func RunApp(ctx context.Context, app *fx.App) error {
 	shutdownComplete := make(chan struct{})
 	go func() {
 		defer close(shutdownComplete)
+
 		<-sigChan
 		log.Notice("Received interrupt signal, shutting down gracefully...")
 
-		// Create a timeout context for shutdown
-		shutdownCtx, shutdownCancel := context.WithTimeout(context.Background(), 30*time.Second)
+		// Create a timeout context for shutdown. The parent ctx is being
+		// cancelled, so detach from its cancellation but keep its values.
+		shutdownCtx, shutdownCancel := context.WithTimeout(
+			context.WithoutCancel(ctx), shutdownTimeout)
 		defer shutdownCancel()
 
-		if err := app.Stop(shutdownCtx); err != nil {
+		err := app.Stop(shutdownCtx)
+		if err != nil {
 			log.Error("Error during shutdown", "error", err)
 		}
 	}()
 
-	// Wait for either the signal handler to complete shutdown or the app to request shutdown
+	// Wait for the signal handler to complete shutdown or the app to
+	// request shutdown.
 	select {
 	case <-shutdownComplete:
 		// Shutdown completed via signal
 		return nil
 	case <-ctx.Done():
 		// Context cancelled (shouldn't happen in normal operation)
-		if err := app.Stop(context.Background()); err != nil {
+		err := app.Stop(context.WithoutCancel(ctx))
+		if err != nil {
 			log.Error("Error stopping app", "error", err)
 		}
+
 		return ctx.Err()
 	case <-app.Done():
 		// App finished running (e.g., backup completed)
@@ -159,6 +195,68 @@ func RunApp(ctx context.Context, app *fx.App) error {
 	}
 }
 
+// runVaultikApp runs the standard single-operation command lifecycle
+// shared by the list/purge/verify/remove/remote-info subcommands:
+// resolve the config, start the fx app, run op against the Vaultik
+// instance in a goroutine, report a failure prefixed with failMsg
+// (suppressed while suppressErrors is true, e.g. under --json), then
+// trigger shutdown. The operation is cancelled when the app stops.
+// extraQuiet is OR-ed into LogOptions.Quiet (e.g. --json output modes).
+func runVaultikApp(
+	cmd *cobra.Command, extraQuiet, suppressErrors bool,
+	failMsg string, op func(v *vaultik.Vaultik) error,
+) error {
+	configPath, err := ResolveConfigPath()
+	if err != nil {
+		return err
+	}
+
+	rootFlags := GetRootFlags()
+
+	return RunWithApp(cmd.Context(), AppOptions{
+		ConfigPath: configPath,
+		LogOptions: log.Options{
+			Verbose: rootFlags.Verbose,
+			Debug:   rootFlags.Debug,
+			Quiet:   rootFlags.Quiet || extraQuiet,
+		},
+		Modules: []fx.Option{},
+		Invokes: []fx.Option{
+			fx.Invoke(func(v *vaultik.Vaultik, lc fx.Lifecycle) {
+				lc.Append(fx.Hook{
+					OnStart: func(_ context.Context) error {
+						go func() {
+							err := op(v)
+							if err != nil {
+								if !errors.Is(err, context.Canceled) {
+									if !suppressErrors {
+										log.Error(failMsg, "error", err)
+										ReportErrorf("%s: %v", failMsg, err)
+									}
+
+									os.Exit(1)
+								}
+							}
+
+							err = v.Shutdowner.Shutdown()
+							if err != nil {
+								log.Error("Failed to shutdown", "error", err)
+							}
+						}()
+
+						return nil
+					},
+					OnStop: func(_ context.Context) error {
+						v.Cancel()
+
+						return nil
+					},
+				})
+			}),
+		},
+	})
+}
+
 // RunWithApp is a helper that creates and runs an fx app with the given options.
 // It combines NewApp and RunApp into a single convenient function. This is the
 // preferred way to run CLI commands that need the full application context.
@@ -166,19 +264,24 @@ func RunApp(ctx context.Context, app *fx.App) error {
 func RunWithApp(ctx context.Context, opts AppOptions) error {
 	// Acquire PID lock to prevent concurrent instances
 	lockDir := filepath.Join(xdg.DataHome, "vaultik")
+
 	lock, err := pidlock.Acquire(lockDir)
 	if err != nil {
 		if errors.Is(err, pidlock.ErrAlreadyRunning) {
 			return fmt.Errorf("cannot start: %w", err)
 		}
+
 		return fmt.Errorf("failed to acquire lock: %w", err)
 	}
+
 	defer func() {
-		if err := lock.Release(); err != nil {
+		err := lock.Release()
+		if err != nil {
 			log.Warn("Failed to release PID lock", "error", err)
 		}
 	}()
 
 	app := NewApp(opts)
+
 	return RunApp(ctx, app)
 }

internal/cli/app_test.go

@@ -1,4 +1,4 @@
-package cli
+package cli //nolint:testpackage // needs access to unexported cleanStartupError
 
 import (
 	"errors"
@@ -6,6 +6,8 @@ import (
 )
 
 func TestCleanStartupError(t *testing.T) {
+	t.Parallel()
+
 	tests := []struct {
 		name string
 		in   string
@@ -13,7 +15,18 @@ func TestCleanStartupError(t *testing.T) {
 	}{
 		{
 			name: "real fx error chain",
-			in:   `could not build arguments for function "sneak.berlin/go/vaultik/internal/cli".newSnapshotCreateCommand.func1.1 (/Users/user/dev/vaultik/internal/cli/snapshot.go:71): failed to build *vaultik.Vaultik: could not build arguments for function "sneak.berlin/go/vaultik/internal/vaultik".New (/Users/user/dev/vaultik/internal/vaultik/vaultik.go:59): failed to build storage.Storer: received non-nil error from function "sneak.berlin/go/vaultik/internal/storage".NewStorer (/Users/user/dev/vaultik/internal/storage/module.go:23): creating base path: mkdir /Volumes/BACKUPS: permission denied`,
+			in: `could not build arguments for function ` +
+				`"sneak.berlin/go/vaultik/internal/cli".newSnapshotCreateCommand.func1.1 ` +
+				`(/Users/user/dev/vaultik/internal/cli/snapshot.go:71): ` +
+				`failed to build *vaultik.Vaultik: ` +
+				`could not build arguments for function ` +
+				`"sneak.berlin/go/vaultik/internal/vaultik".New ` +
+				`(/Users/user/dev/vaultik/internal/vaultik/vaultik.go:59): ` +
+				`failed to build storage.Storer: ` +
+				`received non-nil error from function ` +
+				`"sneak.berlin/go/vaultik/internal/storage".NewStorer ` +
+				`(/Users/user/dev/vaultik/internal/storage/module.go:23): ` +
+				`creating base path: mkdir /Volumes/BACKUPS: permission denied`,
 			want: `creating base path: mkdir /Volumes/BACKUPS: permission denied`,
 		},
 		{
@@ -30,6 +43,9 @@ func TestCleanStartupError(t *testing.T) {
 
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
+
+			//nolint:err113 // test constructs errors from table input
 			got := cleanStartupError(errors.New(tt.in)).Error()
 			if got != tt.want {
 				t.Errorf("got %q, want %q", got, tt.want)

internal/cli/config.go

@@ -1,6 +1,7 @@
 package cli
 
 import (
+	"errors"
 	"fmt"
 	"os"
 	"os/exec"
@@ -12,6 +13,26 @@ import (
 	"gopkg.in/yaml.v3"
 )
 
+// configFileMode is the permission set for freshly written config files;
+// configs may hold S3 credentials, so keep them owner-only.
+const configFileMode = 0o600
+
+// configSetArgs is the argument count of `config set <key> <value>`.
+const configSetArgs = 2
+
+// configDirMode is the permission set for created config directories;
+// parent config dirs (e.g. ~/.config) are conventionally traversable.
+const configDirMode = 0o755
+
+var (
+	errConfigExists     = errors.New("config file already exists")
+	errEmptyConfig      = errors.New("empty config file")
+	errKeyNotFound      = errors.New("key not found")
+	errNeedNumericIndex = errors.New("key is a list; use a numeric index")
+	errIndexOutOfRange  = errors.New("index out of range")
+	errNotMapOrList     = errors.New("key is not a map or list")
+)
+
 const defaultConfigTemplate = `# vaultik configuration
 # Documentation: https://sneak.berlin/go/vaultik
 
@@ -232,24 +253,30 @@ The config is written to the path from --config, $VAULTIK_CONFIG, or
 the platform default config directory (e.g. ~/Library/Application Support/
 on macOS, ~/.config/ on Linux, /etc/vaultik/ as root).`,
 		Args: cobra.NoArgs,
-		RunE: func(cmd *cobra.Command, args []string) error {
+		RunE: func(_ *cobra.Command, _ []string) error {
 			path := configPathForInit()
 
-			if _, err := os.Stat(path); err == nil {
-				return fmt.Errorf("config file already exists: %s", path)
+			_, err := os.Stat(path)
+			if err == nil {
+				return fmt.Errorf("%w: %s", errConfigExists, path)
 			}
 
 			dir := filepath.Dir(path)
-			if err := os.MkdirAll(dir, 0o755); err != nil {
+
+			err = os.MkdirAll(dir, configDirMode)
+			if err != nil {
 				return fmt.Errorf("creating config directory %s: %w", dir, err)
 			}
 
-			if err := os.WriteFile(path, []byte(defaultConfigTemplate), 0o600); err != nil {
+			err = os.WriteFile(path, []byte(defaultConfigTemplate), configFileMode)
+			if err != nil {
 				return fmt.Errorf("writing config file: %w", err)
 			}
 
-			fmt.Printf("Config written to %s\n", path)
-			fmt.Println("Edit it to set your age_recipients, snapshots, and storage_url.")
+			_, _ = fmt.Fprintf(os.Stdout, "Config written to %s\n", path)
+			_, _ = fmt.Fprintln(os.Stdout,
+				"Edit it to set your age_recipients, snapshots, and storage_url.")
+
 			return nil
 		},
 	}
@@ -261,7 +288,7 @@ func newConfigEditCommand() *cobra.Command {
 		Use:   "edit",
 		Short: "Open the config file in $EDITOR",
 		Args:  cobra.NoArgs,
-		RunE: func(cmd *cobra.Command, args []string) error {
+		RunE: func(cmd *cobra.Command, _ []string) error {
 			path, err := ResolveConfigPath()
 			if err != nil {
 				return err
@@ -272,10 +299,12 @@ func newConfigEditCommand() *cobra.Command {
 				editor = "vi"
 			}
 
-			ed := exec.Command(editor, path)
+			//nolint:gosec // G204: launching the operator's own $EDITOR is the point
+			ed := exec.CommandContext(cmd.Context(), editor, path)
 			ed.Stdin = os.Stdin
 			ed.Stdout = os.Stdout
 			ed.Stderr = os.Stderr
+
 			return ed.Run()
 		},
 	}
@@ -287,7 +316,7 @@ func newConfigGetCommand() *cobra.Command {
 		Use:   "get <key>",
 		Short: "Print a config value by dotted path (e.g. storage_url, compression_level)",
 		Args:  cobra.ExactArgs(1),
-		RunE: func(cmd *cobra.Command, args []string) error {
+		RunE: func(_ *cobra.Command, args []string) error {
 			path, err := ResolveConfigPath()
 			if err != nil {
 				return err
@@ -304,7 +333,8 @@ func newConfigGetCommand() *cobra.Command {
 			}
 
 			if node.Kind == yaml.ScalarNode {
-				fmt.Println(node.Value)
+				_, _ = fmt.Fprintln(os.Stdout, node.Value)
+
 				return nil
 			}
 
@@ -312,7 +342,9 @@ func newConfigGetCommand() *cobra.Command {
 			if err != nil {
 				return fmt.Errorf("marshaling value: %w", err)
 			}
-			fmt.Print(string(out))
+
+			_, _ = fmt.Fprint(os.Stdout, string(out))
+
 			return nil
 		},
 	}
@@ -332,8 +364,8 @@ Examples:
   vaultik config set storage_url "s3://bucket/prefix?endpoint=host&region=us-east-1"
   vaultik config set compression_level 9
   vaultik config set s3.bucket mybucket  # legacy S3 fields still supported`,
-		Args: cobra.ExactArgs(2),
-		RunE: func(cmd *cobra.Command, args []string) error {
+		Args: cobra.ExactArgs(configSetArgs),
+		RunE: func(_ *cobra.Command, args []string) error {
 			path, err := ResolveConfigPath()
 			if err != nil {
 				return err
@@ -344,7 +376,8 @@ Examples:
 				return err
 			}
 
-			if err := yamlPathSet(root, strings.Split(args[0], "."), args[1]); err != nil {
+			err = yamlPathSet(root, strings.Split(args[0], "."), args[1])
+			if err != nil {
 				return err
 			}
 
@@ -353,16 +386,20 @@ Examples:
 				return fmt.Errorf("marshaling config: %w", err)
 			}
 
-			mode := os.FileMode(0o600)
-			if info, err := os.Stat(path); err == nil {
+			mode := os.FileMode(configFileMode)
+
+			info, statErr := os.Stat(path)
+			if statErr == nil {
 				mode = info.Mode().Perm()
 			}
 
-			if err := os.WriteFile(path, out, mode); err != nil {
+			err = os.WriteFile(path, out, mode)
+			if err != nil {
 				return fmt.Errorf("writing config file: %w", err)
 			}
 
-			fmt.Printf("%s = %s\n", args[0], args[1])
+			_, _ = fmt.Fprintf(os.Stdout, "%s = %s\n", args[0], args[1])
+
 			return nil
 		},
 	}
@@ -371,13 +408,15 @@ Examples:
 // loadYAMLFile parses a YAML file into a yaml.Node document tree,
 // which preserves comments and ordering for round-tripping.
 func loadYAMLFile(path string) (*yaml.Node, error) {
-	data, err := os.ReadFile(path)
+	data, err := os.ReadFile(path) //nolint:gosec // G304: config path is operator-supplied
 	if err != nil {
 		return nil, fmt.Errorf("reading config file: %w", err)
 	}
 
 	var root yaml.Node
-	if err := yaml.Unmarshal(data, &root); err != nil {
+
+	err = yaml.Unmarshal(data, &root)
+	if err != nil {
 		return nil, fmt.Errorf("parsing config file: %w", err)
 	}
 
@@ -399,8 +438,9 @@ func yamlPathGet(root *yaml.Node, keys []string) (*yaml.Node, error) {
 	node := root
 	if node.Kind == yaml.DocumentNode {
 		if len(node.Content) == 0 {
-			return nil, fmt.Errorf("empty config file")
+			return nil, errEmptyConfig
 		}
+
 		node = node.Content[0]
 	}
 
@@ -408,27 +448,40 @@ func yamlPathGet(root *yaml.Node, keys []string) (*yaml.Node, error) {
 		switch node.Kind {
 		case yaml.MappingNode:
 			found := false
+
 			for j := 0; j+1 < len(node.Content); j += 2 {
 				if node.Content[j].Value == key {
 					node = node.Content[j+1]
 					found = true
+
 					break
 				}
 			}
+
 			if !found {
-				return nil, fmt.Errorf("key not found: %s", strings.Join(keys[:i+1], "."))
+				return nil, fmt.Errorf("%w: %s",
+					errKeyNotFound, strings.Join(keys[:i+1], "."))
 			}
 		case yaml.SequenceNode:
 			idx, err := strconv.Atoi(key)
 			if err != nil {
-				return nil, fmt.Errorf("key %q is a list; use a numeric index", strings.Join(keys[:i], "."))
+				return nil, fmt.Errorf("%w: %s",
+					errNeedNumericIndex, strings.Join(keys[:i], "."))
 			}
+
 			if idx < 0 || idx >= len(node.Content) {
-				return nil, fmt.Errorf("index %d out of range for %s (len %d)", idx, strings.Join(keys[:i], "."), len(node.Content))
+				return nil, fmt.Errorf("%w: index %d for %s (len %d)",
+					errIndexOutOfRange, idx, strings.Join(keys[:i], "."),
+					len(node.Content))
 			}
+
 			node = node.Content[idx]
+		case yaml.DocumentNode, yaml.ScalarNode, yaml.AliasNode:
+			return nil, fmt.Errorf("%w: %s",
+				errNotMapOrList, strings.Join(keys[:i], "."))
 		default:
-			return nil, fmt.Errorf("key %q is not a map or list", strings.Join(keys[:i], "."))
+			return nil, fmt.Errorf("%w: %s",
+				errNotMapOrList, strings.Join(keys[:i], "."))
 		}
 	}
 
@@ -445,6 +498,7 @@ func yamlPathSet(root *yaml.Node, keys []string, value string) error {
 		if len(node.Content) == 0 {
 			node.Content = []*yaml.Node{{Kind: yaml.MappingNode}}
 		}
+
 		node = node.Content[0]
 	}
 
@@ -453,52 +507,86 @@ func yamlPathSet(root *yaml.Node, keys []string, value string) error {
 
 		switch node.Kind {
 		case yaml.MappingNode:
+			node = yamlSetInMapping(node, key, value, last)
+		case yaml.SequenceNode:
+			next, err := yamlSetInSequence(node, keys, i, value, last)
+			if err != nil {
+				return err
+			}
+
+			node = next
+		case yaml.DocumentNode, yaml.ScalarNode, yaml.AliasNode:
+			return fmt.Errorf("%w: %s",
+				errNotMapOrList, strings.Join(keys[:i], "."))
+		default:
+			return fmt.Errorf("%w: %s",
+				errNotMapOrList, strings.Join(keys[:i], "."))
+		}
+	}
+
+	return nil
+}
+
+// yamlSetInMapping resolves (creating if needed) the value node for key
+// within a mapping node, setting it to value when it is the final path
+// element, and returns the node to descend into.
+func yamlSetInMapping(node *yaml.Node, key, value string, last bool) *yaml.Node {
 	var valueNode *yaml.Node
+
 	for j := 0; j+1 < len(node.Content); j += 2 {
 		if node.Content[j].Value == key {
 			valueNode = node.Content[j+1]
+
 			break
 		}
 	}
 
 	if valueNode == nil {
 		keyNode := &yaml.Node{Kind: yaml.ScalarNode, Value: key}
+
 		valueNode = &yaml.Node{Kind: yaml.MappingNode}
 		if last {
 			valueNode = &yaml.Node{Kind: yaml.ScalarNode, Value: value}
 		}
+
 		node.Content = append(node.Content, keyNode, valueNode)
 	} else if last {
 		setScalar(valueNode, value)
 	}
 
-			node = valueNode
+	return valueNode
+}
 
-		case yaml.SequenceNode:
-			idx, err := strconv.Atoi(key)
+// yamlSetInSequence indexes (or appends to) a sequence node using the
+// numeric path element keys[i], setting the element to value when it is
+// the final path element, and returns the node to descend into.
+func yamlSetInSequence(
+	node *yaml.Node, keys []string, i int, value string, last bool,
+) (*yaml.Node, error) {
+	idx, err := strconv.Atoi(keys[i])
 	if err != nil {
-				return fmt.Errorf("key %q is a list; use a numeric index", strings.Join(keys[:i], "."))
+		return nil, fmt.Errorf("%w: %s",
+			errNeedNumericIndex, strings.Join(keys[:i], "."))
 	}
+
 	if idx < 0 || idx > len(node.Content) {
-				return fmt.Errorf("index %d out of range for %s (len %d)", idx, strings.Join(keys[:i], "."), len(node.Content))
+		return nil, fmt.Errorf("%w: index %d for %s (len %d)",
+			errIndexOutOfRange, idx, strings.Join(keys[:i], "."),
+			len(node.Content))
 	}
+
 	if idx == len(node.Content) {
 		newNode := &yaml.Node{Kind: yaml.MappingNode}
 		if last {
 			newNode = &yaml.Node{Kind: yaml.ScalarNode, Value: value}
 		}
+
 		node.Content = append(node.Content, newNode)
 	} else if last {
 		setScalar(node.Content[idx], value)
 	}
-			node = node.Content[idx]
 
-		default:
-			return fmt.Errorf("key %q is not a map or list", strings.Join(keys[:i], "."))
-		}
-	}
-
-	return nil
+	return node.Content[idx], nil
 }
 
 // setScalar overwrites a node in place with a plain scalar value.
@@ -516,8 +604,10 @@ func configPathForInit() string {
 	if rootFlags.ConfigPath != "" {
 		return rootFlags.ConfigPath
 	}
+
 	if envPath := os.Getenv("VAULTIK_CONFIG"); envPath != "" {
 		return envPath
 	}
+
 	return DefaultConfigPath()
 }

internal/cli/config_test.go

@@ -1,4 +1,4 @@
-package cli
+package cli //nolint:testpackage // exercises unexported yamlPathGet/yamlPathSet
 
 import (
 	"strings"
@@ -11,8 +11,12 @@ import (
 // TestDefaultConfigTemplateParses ensures the init template is valid YAML
 // that unmarshals into the Config struct with the expected snapshots.
 func TestDefaultConfigTemplateParses(t *testing.T) {
+	t.Parallel()
+
 	var cfg config.Config
-	if err := yaml.Unmarshal([]byte(defaultConfigTemplate), &cfg); err != nil {
+
+	err := yaml.Unmarshal([]byte(defaultConfigTemplate), &cfg)
+	if err != nil {
 		t.Fatalf("default config template is not valid YAML: %v", err)
 	}
 
@@ -24,9 +28,11 @@ func TestDefaultConfigTemplateParses(t *testing.T) {
 	if !ok {
 		t.Fatal("expected 'home' snapshot in default config")
 	}
+
 	if len(home.Paths) == 0 {
 		t.Error("home snapshot should have at least one path")
 	}
+
 	if len(home.Exclude) == 0 {
 		t.Error("home snapshot should have exclude patterns")
 	}
@@ -35,9 +41,11 @@ func TestDefaultConfigTemplateParses(t *testing.T) {
 	if !ok {
 		t.Fatal("expected 'apps' snapshot in default config")
 	}
+
 	if len(apps.Paths) != 1 || apps.Paths[0] != "/Applications" {
 		t.Errorf("apps snapshot should back up /Applications, got %v", apps.Paths)
 	}
+
 	if len(apps.Exclude) == 0 {
 		t.Error("apps snapshot should have exclude patterns")
 	}
@@ -58,14 +66,20 @@ snapshots:
 
 func parseTestYAML(t *testing.T) *yaml.Node {
 	t.Helper()
+
 	var root yaml.Node
-	if err := yaml.Unmarshal([]byte(testYAML), &root); err != nil {
+
+	err := yaml.Unmarshal([]byte(testYAML), &root)
+	if err != nil {
 		t.Fatalf("parsing test yaml: %v", err)
 	}
+
 	return &root
 }
 
 func TestYAMLPathGet(t *testing.T) {
+	t.Parallel()
+
 	root := parseTestYAML(t)
 
 	tests := []struct {
@@ -86,16 +100,21 @@ func TestYAMLPathGet(t *testing.T) {
 
 	for _, tt := range tests {
 		t.Run(tt.path, func(t *testing.T) {
+			t.Parallel()
+
 			node, err := yamlPathGet(root, splitPath(tt.path))
 			if tt.err {
 				if err == nil {
 					t.Fatalf("expected error for %q", tt.path)
 				}
+
 				return
 			}
+
 			if err != nil {
 				t.Fatalf("unexpected error: %v", err)
 			}
+
 			if node.Value != tt.want {
 				t.Errorf("get %q = %q, want %q", tt.path, node.Value, tt.want)
 			}
@@ -104,29 +123,40 @@ func TestYAMLPathGet(t *testing.T) {
 }
 
 func TestYAMLPathSet(t *testing.T) {
+	t.Parallel()
+
 	root := parseTestYAML(t)
 
 	// Overwrite existing nested value
-	if err := yamlPathSet(root, splitPath("s3.bucket"), "newbucket"); err != nil {
+	err := yamlPathSet(root, splitPath("s3.bucket"), "newbucket")
+	if err != nil {
 		t.Fatalf("set s3.bucket: %v", err)
 	}
 
 	// Create new nested key with intermediate map
-	if err := yamlPathSet(root, splitPath("s3.endpoint"), "s3.example.com"); err != nil {
+	err = yamlPathSet(root, splitPath("s3.endpoint"), "s3.example.com")
+	if err != nil {
 		t.Fatalf("set s3.endpoint: %v", err)
 	}
-	if err := yamlPathSet(root, splitPath("newmap.newkey"), "val"); err != nil {
+
+	err = yamlPathSet(root, splitPath("newmap.newkey"), "val")
+	if err != nil {
 		t.Fatalf("set newmap.newkey: %v", err)
 	}
 
 	// Overwrite a sequence element and append a new one
-	if err := yamlPathSet(root, splitPath("age_recipients.0"), "age1bbb"); err != nil {
+	err = yamlPathSet(root, splitPath("age_recipients.0"), "age1bbb")
+	if err != nil {
 		t.Fatalf("set age_recipients.0: %v", err)
 	}
-	if err := yamlPathSet(root, splitPath("age_recipients.1"), "age1ccc"); err != nil {
+
+	err = yamlPathSet(root, splitPath("age_recipients.1"), "age1ccc")
+	if err != nil {
 		t.Fatalf("append age_recipients.1: %v", err)
 	}
-	if err := yamlPathSet(root, splitPath("age_recipients.5"), "age1ddd"); err == nil {
+
+	err = yamlPathSet(root, splitPath("age_recipients.5"), "age1ddd")
+	if err == nil {
 		t.Error("expected out-of-range append to fail")
 	}
 
@@ -135,9 +165,14 @@ func TestYAMLPathSet(t *testing.T) {
 	if err != nil {
 		t.Fatalf("marshal: %v", err)
 	}
+
 	text := string(out)
 
-	for _, want := range []string{"newbucket", "s3.example.com", "newkey: val", "# top comment", "# inline comment", "age1bbb", "age1ccc"} {
+	wants := []string{
+		"newbucket", "s3.example.com", "newkey: val",
+		"# top comment", "# inline comment", "age1bbb", "age1ccc",
+	}
+	for _, want := range wants {
 		if !contains(text, want) {
 			t.Errorf("round-tripped YAML missing %q:\n%s", want, text)
 		}
@@ -147,6 +182,7 @@ func TestYAMLPathSet(t *testing.T) {
 	if err != nil {
 		t.Fatalf("get after set: %v", err)
 	}
+
 	if got.Value != "newbucket" {
 		t.Errorf("s3.bucket = %q after set, want newbucket", got.Value)
 	}

internal/cli/database.go

@@ -48,7 +48,7 @@ storage destination on that run.
 
 Use --force to skip the confirmation prompt.`,
 		Args: cobra.NoArgs,
-		RunE: func(cmd *cobra.Command, args []string) error {
+		RunE: func(_ *cobra.Command, _ []string) error {
 			// Resolve config path
 			configPath, err := ResolveConfigPath()
 			if err != nil {
@@ -64,24 +64,33 @@ Use --force to skip the confirmation prompt.`,
 			dbPath := cfg.IndexPath
 
 			// Check if database exists
-			if _, err := os.Stat(dbPath); os.IsNotExist(err) {
-				fmt.Printf("Database does not exist: %s\n", dbPath)
+			_, err = os.Stat(dbPath)
+			if os.IsNotExist(err) {
+				_, _ = fmt.Fprintf(os.Stdout, "Database does not exist: %s\n", dbPath)
+
 				return nil
 			}
 
 			// Confirm unless --force
 			if !force {
-				fmt.Printf("This will delete the local state database at:\n  %s\n\n", dbPath)
-				fmt.Print("Are you sure? Type 'yes' to confirm: ")
+				_, _ = fmt.Fprintf(os.Stdout,
+					"This will delete the local state database at:\n  %s\n\n", dbPath)
+				_, _ = fmt.Fprint(os.Stdout, "Are you sure? Type 'yes' to confirm: ")
+
 				var confirm string
-				if _, err := fmt.Scanln(&confirm); err != nil || confirm != "yes" {
-					fmt.Println("Aborted.")
+
+				_, err = fmt.Scanln(&confirm)
+				if err != nil || confirm != "yes" {
+					_, _ = fmt.Fprintln(os.Stdout, "Aborted.")
+
+					//nolint:nilerr // a failed/aborted confirmation is a clean abort
 					return nil
 				}
 			}
 
 			// Delete the database file
-			if err := os.Remove(dbPath); err != nil {
+			err = os.Remove(dbPath)
+			if err != nil {
 				return fmt.Errorf("failed to delete database: %w", err)
 			}
 
@@ -93,10 +102,11 @@ Use --force to skip the confirmation prompt.`,
 
 			rootFlags := GetRootFlags()
 			if !rootFlags.Quiet {
-				fmt.Printf("Database deleted: %s\n", dbPath)
+				_, _ = fmt.Fprintf(os.Stdout, "Database deleted: %s\n", dbPath)
 			}
 
 			log.Info("Local state database deleted", "path", dbPath)
+
 			return nil
 		},
 	}

internal/cli/duration.go

@@ -1,6 +1,7 @@
 package cli
 
 import (
+	"errors"
 	"fmt"
 	"regexp"
 	"strconv"
@@ -8,6 +9,21 @@ import (
 	"time"
 )
 
+// Approximate lengths of the extended calendar units accepted by
+// parseDuration.
+const (
+	durationDay   = 24 * time.Hour
+	durationWeek  = 7 * durationDay
+	durationMonth = 30 * durationDay
+	durationYear  = 365 * durationDay
+)
+
+var (
+	errNegativeDuration = errors.New("negative durations are not supported")
+	errInvalidDuration  = errors.New("invalid duration format")
+	errUnknownTimeUnit  = errors.New("unknown time unit")
+)
+
 // parseDuration parses duration strings. Supports standard Go duration format
 // (e.g., "3h30m", "1h45m30s") as well as extended units:
 // - d: days (e.g., "30d", "7d")
@@ -18,14 +34,15 @@ import (
 // Can combine units: "1y6mo", "2w3d", "1d12h30m"
 func parseDuration(s string) (time.Duration, error) {
 	// First try standard Go duration parsing
-	if d, err := time.ParseDuration(s); err == nil {
+	d, err := time.ParseDuration(s)
+	if err == nil {
 		return d, nil
 	}
 
 	// Extended duration parsing
 	// Check for negative values
 	if strings.HasPrefix(strings.TrimSpace(s), "-") {
-		return 0, fmt.Errorf("negative durations are not supported")
+		return 0, errNegativeDuration
 	}
 
 	// Pattern matches: number + unit, repeated
@@ -33,7 +50,7 @@ func parseDuration(s string) (time.Duration, error) {
 	matches := re.FindAllStringSubmatch(s, -1)
 
 	if len(matches) == 0 {
-		return 0, fmt.Errorf("invalid duration format: %q", s)
+		return 0, fmt.Errorf("%w: %q", errInvalidDuration, s)
 	}
 
 	var total time.Duration
@@ -47,44 +64,9 @@ func parseDuration(s string) (time.Duration, error) {
 			return 0, fmt.Errorf("invalid number %q: %w", valueStr, err)
 		}
 
-		var d time.Duration
-		switch unit {
-		// Standard time units
-		case "ns", "nanosecond", "nanoseconds":
-			d = time.Duration(value)
-		case "us", "µs", "microsecond", "microseconds":
-			d = time.Duration(value * float64(time.Microsecond))
-		case "ms", "millisecond", "milliseconds":
-			d = time.Duration(value * float64(time.Millisecond))
-		case "s", "sec", "second", "seconds":
-			d = time.Duration(value * float64(time.Second))
-		case "m", "min", "minute", "minutes":
-			d = time.Duration(value * float64(time.Minute))
-		case "h", "hr", "hour", "hours":
-			d = time.Duration(value * float64(time.Hour))
-		// Extended units
-		case "d", "day", "days":
-			d = time.Duration(value * float64(24*time.Hour))
-		case "w", "week", "weeks":
-			d = time.Duration(value * float64(7*24*time.Hour))
-		case "mo", "month", "months":
-			// Using 30 days as approximation
-			d = time.Duration(value * float64(30*24*time.Hour))
-		case "y", "year", "years":
-			// Using 365 days as approximation
-			d = time.Duration(value * float64(365*24*time.Hour))
-		default:
-			// Try parsing as standard Go duration unit
-			testStr := fmt.Sprintf("1%s", unit)
-			if _, err := time.ParseDuration(testStr); err == nil {
-				// It's a valid Go duration unit, parse the full value
-				fullStr := fmt.Sprintf("%g%s", value, unit)
-				if d, err = time.ParseDuration(fullStr); err != nil {
-					return 0, fmt.Errorf("invalid duration %q: %w", fullStr, err)
-				}
-			} else {
-				return 0, fmt.Errorf("unknown time unit %q", unit)
-			}
+		d, err := durationForUnit(value, unit)
+		if err != nil {
+			return 0, err
 		}
 
 		total += d
@@ -92,3 +74,53 @@ func parseDuration(s string) (time.Duration, error) {
 
 	return total, nil
 }
+
+// durationForUnit converts a value with a (case-normalized) unit suffix
+// into a time.Duration, accepting Go's standard units plus the extended
+// calendar units.
+func durationForUnit(value float64, unit string) (time.Duration, error) {
+	switch unit {
+	// Standard time units
+	case "ns", "nanosecond", "nanoseconds":
+		return time.Duration(value), nil
+	case "us", "µs", "microsecond", "microseconds":
+		return time.Duration(value * float64(time.Microsecond)), nil
+	case "ms", "millisecond", "milliseconds":
+		return time.Duration(value * float64(time.Millisecond)), nil
+	case "s", "sec", "second", "seconds":
+		return time.Duration(value * float64(time.Second)), nil
+	case "m", "min", "minute", "minutes":
+		return time.Duration(value * float64(time.Minute)), nil
+	case "h", "hr", "hour", "hours":
+		return time.Duration(value * float64(time.Hour)), nil
+	// Extended units
+	case "d", "day", "days":
+		return time.Duration(value * float64(durationDay)), nil
+	case "w", "week", "weeks":
+		return time.Duration(value * float64(durationWeek)), nil
+	case "mo", "month", "months":
+		// Using 30 days as approximation
+		return time.Duration(value * float64(durationMonth)), nil
+	case "y", "year", "years":
+		// Using 365 days as approximation
+		return time.Duration(value * float64(durationYear)), nil
+	default:
+		// Try parsing as standard Go duration unit
+		testStr := "1" + unit
+
+		_, err := time.ParseDuration(testStr)
+		if err != nil {
+			return 0, fmt.Errorf("%w: %q", errUnknownTimeUnit, unit)
+		}
+
+		// It's a valid Go duration unit, parse the full value
+		fullStr := fmt.Sprintf("%g%s", value, unit)
+
+		d, err := time.ParseDuration(fullStr)
+		if err != nil {
+			return 0, fmt.Errorf("invalid duration %q: %w", fullStr, err)
+		}
+
+		return d, nil
+	}
+}

internal/cli/duration_test.go

@@ -1,20 +1,47 @@
-package cli
+package cli //nolint:testpackage // needs access to unexported parseDuration
 
 import (
 	"testing"
 	"time"
 
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 )
 
-func TestParseDuration(t *testing.T) {
-	tests := []struct {
+type parseDurationCase struct {
 	name     string
 	input    string
 	expected time.Duration
 	wantErr  bool
-	}{
-		// Standard Go durations
+}
+
+// runParseDurationCases executes a table of parseDuration cases as
+// parallel subtests.
+func runParseDurationCases(t *testing.T, tests []parseDurationCase) {
+	t.Helper()
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
+
+			got, err := parseDuration(tt.input)
+
+			if tt.wantErr {
+				require.Error(t, err, "expected error for input %q", tt.input)
+
+				return
+			}
+
+			require.NoError(t, err, "unexpected error for input %q", tt.input)
+			assert.Equal(t, tt.expected, got, "duration mismatch for input %q", tt.input)
+		})
+	}
+}
+
+func TestParseDurationStandard(t *testing.T) {
+	t.Parallel()
+
+	runParseDurationCases(t, []parseDurationCase{
 		{
 			name:     "standard seconds",
 			input:    "30s",
@@ -45,6 +72,13 @@ func TestParseDuration(t *testing.T) {
 			input:    "1s500ms",
 			expected: 1*time.Second + 500*time.Millisecond,
 		},
+	})
+}
+
+func TestParseDurationExtendedUnits(t *testing.T) {
+	t.Parallel()
+
+	runParseDurationCases(t, []parseDurationCase{
 		// Extended units - days
 		{
 			name:     "single day",
@@ -114,6 +148,13 @@ func TestParseDuration(t *testing.T) {
 			input:    "1year",
 			expected: 365 * 24 * time.Hour,
 		},
+	})
+}
+
+func TestParseDurationCombinedAndErrors(t *testing.T) {
+	t.Parallel()
+
+	runParseDurationCases(t, []parseDurationCase{
 		// Combined extended units
 		{
 			name:     "weeks and days",
@@ -133,7 +174,9 @@ func TestParseDuration(t *testing.T) {
 		{
 			name:  "complex combination",
 			input: "1y2mo3w4d5h6m7s",
-			expected: 365*24*time.Hour + 2*30*24*time.Hour + 3*7*24*time.Hour + 4*24*time.Hour + 5*time.Hour + 6*time.Minute + 7*time.Second,
+			expected: 365*24*time.Hour + 2*30*24*time.Hour +
+				3*7*24*time.Hour + 4*24*time.Hour +
+				5*time.Hour + 6*time.Minute + 7*time.Second,
 		},
 		{
 			name:     "with spaces",
@@ -177,24 +220,12 @@ func TestParseDuration(t *testing.T) {
 			input:   "-5d",
 			wantErr: true,
 		},
-	}
-
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			got, err := parseDuration(tt.input)
-
-			if tt.wantErr {
-				assert.Error(t, err, "expected error for input %q", tt.input)
-				return
-			}
-
-			assert.NoError(t, err, "unexpected error for input %q", tt.input)
-			assert.Equal(t, tt.expected, got, "duration mismatch for input %q", tt.input)
 	})
-	}
 }
 
 func TestParseDurationSpecialCases(t *testing.T) {
+	t.Parallel()
+
 	// Test that standard Go durations work exactly as expected
 	standardDurations := []string{
 		"300ms",
@@ -208,15 +239,17 @@ func TestParseDurationSpecialCases(t *testing.T) {
 
 	for _, d := range standardDurations {
 		expected, err := time.ParseDuration(d)
-		assert.NoError(t, err)
+		require.NoError(t, err)
 
 		got, err := parseDuration(d)
-		assert.NoError(t, err)
+		require.NoError(t, err)
 		assert.Equal(t, expected, got, "standard duration %q should parse identically", d)
 	}
 }
 
 func TestParseDurationRealWorldExamples(t *testing.T) {
+	t.Parallel()
+
 	// Test real-world snapshot purge scenarios
 	tests := []struct {
 		description string
@@ -252,12 +285,15 @@ func TestParseDurationRealWorldExamples(t *testing.T) {
 
 	for _, tt := range tests {
 		t.Run(tt.description, func(t *testing.T) {
+			t.Parallel()
+
 			got, err := parseDuration(tt.input)
-			assert.NoError(t, err)
+			require.NoError(t, err)
 			assert.Equal(t, tt.olderThan, got)
 
 			// Verify the duration makes sense for snapshot purging
-			assert.Greater(t, got, time.Hour, "snapshot purge duration should be at least an hour")
+			assert.Greater(t, got, time.Hour,
+				"snapshot purge duration should be at least an hour")
 		})
 	}
 }

internal/cli/entry.go

@@ -9,34 +9,40 @@ import (
 	"sneak.berlin/go/vaultik/internal/ui"
 )
 
-// CLIEntry is the main entry point for the CLI application.
+// shortCommitLen is the number of git commit hash characters shown in
+// the startup banner.
+const shortCommitLen = 12
+
+// Entry is the main entry point for the CLI application.
 // It prints the startup banner (unless a quiet flag is present in os.Args),
 // executes the root cobra command, and routes any returned error through
 // the ui.Writer so the user sees a properly formatted "🛑 ERROR:" line.
-func CLIEntry() {
+func Entry() {
 	if !bannerSuppressedInArgs(os.Args[1:]) {
 		short := globals.Commit
-		if len(short) > 12 {
-			short = short[:12]
+		if len(short) > shortCommitLen {
+			short = short[:shortCommitLen]
 		}
+
 		writeStartupBanner(ui.New(os.Stdout), time.Now().UTC(), short)
 	}
 
 	rootCmd := NewRootCommand()
 	rootCmd.SilenceErrors = true
 
-	if err := rootCmd.Execute(); err != nil {
-		ReportError("%s", err.Error())
+	err := rootCmd.Execute()
+	if err != nil {
+		ReportErrorf("%s", err.Error())
 		os.Exit(1)
 	}
 }
 
-// ReportError emits a user-facing error to stderr in the standard
+// ReportErrorf emits a user-facing error to stderr in the standard
 // 🛑 ERROR: format. Use it from goroutine error paths (where returning
 // an error to cobra isn't an option) and anywhere else a CLI command
 // must surface a failure outside the normal RunE return path.
-func ReportError(format string, args ...any) {
-	ui.New(os.Stderr).Error(format, args...)
+func ReportErrorf(format string, args ...any) {
+	ui.New(os.Stderr).Errorf(format, args...)
 }
 
 // bannerSuppressedInArgs reports whether any of args is a flag that
@@ -48,10 +54,12 @@ func bannerSuppressedInArgs(args []string) bool {
 		if a == "--" {
 			return false
 		}
+
 		switch a {
 		case "--quiet", "-q", "--cron":
 			return true
 		}
+
 		if strings.HasPrefix(a, "--quiet=") || strings.HasPrefix(a, "--cron=") {
 			return true
 		}
@@ -64,5 +72,6 @@ func bannerSuppressedInArgs(args []string) bool {
 			}
 		}
 	}
+
 	return false
 }

internal/cli/entry_test.go

@@ -1,14 +1,18 @@
-package cli
+package cli_test
 
 import (
 	"testing"
+
+	"sneak.berlin/go/vaultik/internal/cli"
 )
 
 // TestCLIEntry ensures the CLI can be imported and basic initialization works
 func TestCLIEntry(t *testing.T) {
+	t.Parallel()
+
 	// This test primarily serves as a compilation test
 	// to ensure all imports resolve correctly
-	cmd := NewRootCommand()
+	cmd := cli.NewRootCommand()
 	if cmd == nil {
 		t.Fatal("NewRootCommand() returned nil")
 	}
@@ -18,15 +22,20 @@ func TestCLIEntry(t *testing.T) {
 	}
 
 	// Verify all subcommands are registered
-	expectedCommands := []string{"config", "snapshot", "prune", "info", "version", "remote", "database"}
+	expectedCommands := []string{
+		"config", "snapshot", "prune", "info", "version", "remote", "database",
+	}
 	for _, expected := range expectedCommands {
 		found := false
+
 		for _, cmd := range cmd.Commands() {
 			if cmd.Use == expected || cmd.Name() == expected {
 				found = true
+
 				break
 			}
 		}
+
 		if !found {
 			t.Errorf("Expected command '%s' not found", expected)
 		}
@@ -38,15 +47,20 @@ func TestCLIEntry(t *testing.T) {
 		t.Errorf("Failed to find snapshot command: %v", err)
 	} else {
 		// Check snapshot subcommands
-		expectedSubCommands := []string{"create", "list", "purge", "verify", "remove", "restore"}
+		expectedSubCommands := []string{
+			"create", "list", "purge", "verify", "remove", "restore",
+		}
 		for _, expected := range expectedSubCommands {
 			found := false
+
 			for _, subcmd := range snapshotCmd.Commands() {
 				if subcmd.Use == expected || subcmd.Name() == expected {
 					found = true
+
 					break
 				}
 			}
+
 			if !found {
 				t.Errorf("Expected snapshot subcommand '%s' not found", expected)
 			}

internal/cli/info.go

@@ -2,6 +2,7 @@ package cli
 
 import (
 	"context"
+	"errors"
 	"os"
 
 	"github.com/spf13/cobra"
@@ -22,7 +23,7 @@ func NewInfoCommand() *cobra.Command {
 - Encryption configuration (recipients)
 - Local database statistics`,
 		Args: cobra.NoArgs,
-		RunE: func(cmd *cobra.Command, args []string) error {
+		RunE: func(cmd *cobra.Command, _ []string) error {
 			// Use unified config resolution
 			configPath, err := ResolveConfigPath()
 			if err != nil {
@@ -31,9 +32,10 @@ func NewInfoCommand() *cobra.Command {
 
 			// Use the app framework
 			rootFlags := GetRootFlags()
+
 			return RunWithApp(cmd.Context(), AppOptions{
 				ConfigPath: configPath,
-				LogOptions: log.LogOptions{
+				LogOptions: log.Options{
 					Verbose: rootFlags.Verbose,
 					Debug:   rootFlags.Debug,
 					Quiet:   rootFlags.Quiet,
@@ -42,23 +44,28 @@ func NewInfoCommand() *cobra.Command {
 				Invokes: []fx.Option{
 					fx.Invoke(func(v *vaultik.Vaultik, lc fx.Lifecycle) {
 						lc.Append(fx.Hook{
-							OnStart: func(ctx context.Context) error {
+							OnStart: func(_ context.Context) error {
 								go func() {
-									if err := v.ShowInfo(); err != nil {
-										if err != context.Canceled {
+									err := v.ShowInfo()
+									if err != nil {
+										if !errors.Is(err, context.Canceled) {
 											log.Error("Failed to show info", "error", err)
-											ReportError("Failed to show info: %v", err)
+											ReportErrorf("Failed to show info: %v", err)
 											os.Exit(1)
 										}
 									}
-									if err := v.Shutdowner.Shutdown(); err != nil {
+
+									err = v.Shutdowner.Shutdown()
+									if err != nil {
 										log.Error("Failed to shutdown", "error", err)
 									}
 								}()
+
 								return nil
 							},
-							OnStop: func(ctx context.Context) error {
+							OnStop: func(_ context.Context) error {
 								v.Cancel()
+
 								return nil
 							},
 						})

internal/cli/prune.go

@@ -2,6 +2,7 @@ package cli
 
 import (
 	"context"
+	"errors"
 	"os"
 
 	"github.com/spf13/cobra"
@@ -30,7 +31,7 @@ Snapshot create --prune and snapshot remove run the same cleanup
 automatically; this command is the manual entry point for the same
 work (e.g. after a crashed backup or to reclaim storage).`,
 		Args: cobra.NoArgs,
-		RunE: func(cmd *cobra.Command, args []string) error {
+		RunE: func(cmd *cobra.Command, _ []string) error {
 			// Use unified config resolution
 			configPath, err := ResolveConfigPath()
 			if err != nil {
@@ -39,9 +40,10 @@ work (e.g. after a crashed backup or to reclaim storage).`,
 
 			// Use the app framework like other commands
 			rootFlags := GetRootFlags()
+
 			return RunWithApp(cmd.Context(), AppOptions{
 				ConfigPath: configPath,
-				LogOptions: log.LogOptions{
+				LogOptions: log.Options{
 					Verbose: rootFlags.Verbose,
 					Debug:   rootFlags.Debug,
 					Quiet:   rootFlags.Quiet || opts.JSON,
@@ -50,30 +52,35 @@ work (e.g. after a crashed backup or to reclaim storage).`,
 				Invokes: []fx.Option{
 					fx.Invoke(func(v *vaultik.Vaultik, lc fx.Lifecycle) {
 						lc.Append(fx.Hook{
-							OnStart: func(ctx context.Context) error {
+							OnStart: func(_ context.Context) error {
 								// Start the prune operation in a goroutine
 								go func() {
 									// Run the prune operation
-									if err := v.Prune(opts); err != nil {
-										if err != context.Canceled {
+									err := v.Prune(opts)
+									if err != nil {
+										if !errors.Is(err, context.Canceled) {
 											if !opts.JSON {
 												log.Error("Prune operation failed", "error", err)
-												ReportError("Prune failed: %v", err)
+												ReportErrorf("Prune failed: %v", err)
 											}
+
 											os.Exit(1)
 										}
 									}
 
 									// Shutdown the app when prune completes
-									if err := v.Shutdowner.Shutdown(); err != nil {
+									err = v.Shutdowner.Shutdown()
+									if err != nil {
 										log.Error("Failed to shutdown", "error", err)
 									}
 								}()
+
 								return nil
 							},
-							OnStop: func(ctx context.Context) error {
+							OnStop: func(_ context.Context) error {
 								log.Debug("Stopping prune operation")
 								v.Cancel()
+
 								return nil
 							},
 						})

internal/cli/remote.go

@@ -2,7 +2,7 @@ package cli
 
 import (
 	"context"
-	"fmt"
+	"errors"
 	"os"
 
 	"github.com/spf13/cobra"
@@ -11,6 +11,10 @@ import (
 	"sneak.berlin/go/vaultik/internal/vaultik"
 )
 
+// errNukeNeedsForce guards the destructive 'remote nuke' subcommand.
+var errNukeNeedsForce = errors.New(
+	"remote nuke requires --force (this deletes ALL remote snapshots and blobs)")
+
 // NewRemoteCommand creates the remote command and subcommands
 func NewRemoteCommand() *cobra.Command {
 	cmd := &cobra.Command{
@@ -39,55 +43,20 @@ empty and the next backup starts from scratch.
 
 This is destructive and irreversible. Requires --force.`,
 		Args: cobra.NoArgs,
-		RunE: func(cmd *cobra.Command, args []string) error {
+		RunE: func(cmd *cobra.Command, _ []string) error {
 			if !force {
-				return fmt.Errorf("remote nuke requires --force (this deletes ALL remote snapshots and blobs)")
+				return errNukeNeedsForce
 			}
 
-			configPath, err := ResolveConfigPath()
-			if err != nil {
-				return err
-			}
-
-			rootFlags := GetRootFlags()
-			return RunWithApp(cmd.Context(), AppOptions{
-				ConfigPath: configPath,
-				LogOptions: log.LogOptions{
-					Verbose: rootFlags.Verbose,
-					Debug:   rootFlags.Debug,
-					Quiet:   rootFlags.Quiet,
-				},
-				Modules: []fx.Option{},
-				Invokes: []fx.Option{
-					fx.Invoke(func(v *vaultik.Vaultik, lc fx.Lifecycle) {
-						lc.Append(fx.Hook{
-							OnStart: func(ctx context.Context) error {
-								go func() {
-									if err := v.NukeRemote(true); err != nil {
-										if err != context.Canceled {
-											log.Error("Remote nuke failed", "error", err)
-											ReportError("Remote nuke failed: %v", err)
-											os.Exit(1)
-										}
-									}
-									if err := v.Shutdowner.Shutdown(); err != nil {
-										log.Error("Failed to shutdown", "error", err)
-									}
-								}()
-								return nil
-							},
-							OnStop: func(ctx context.Context) error {
-								v.Cancel()
-								return nil
-							},
-						})
-					}),
-				},
+			return runVaultikApp(cmd, false, false, "Remote nuke failed",
+				func(v *vaultik.Vaultik) error {
+					return v.NukeRemote(true)
 				})
 		},
 	}
 
-	cmd.Flags().BoolVar(&force, "force", false, "Required: confirm destruction of ALL remote data")
+	cmd.Flags().BoolVar(&force, "force", false,
+		"Required: confirm destruction of ALL remote data")
 
 	return cmd
 }
@@ -105,7 +74,7 @@ func newRemoteInfoCommand() *cobra.Command {
 - Count and size of referenced blobs (from all manifests)
 - Count and size of orphaned blobs (not referenced by any manifest)`,
 		Args: cobra.NoArgs,
-		RunE: func(cmd *cobra.Command, args []string) error {
+		RunE: func(cmd *cobra.Command, _ []string) error {
 			// Use unified config resolution
 			configPath, err := ResolveConfigPath()
 			if err != nil {
@@ -113,9 +82,10 @@ func newRemoteInfoCommand() *cobra.Command {
 			}
 
 			rootFlags := GetRootFlags()
+
 			return RunWithApp(cmd.Context(), AppOptions{
 				ConfigPath: configPath,
-				LogOptions: log.LogOptions{
+				LogOptions: log.Options{
 					Verbose: rootFlags.Verbose,
 					Debug:   rootFlags.Debug,
 					Quiet:   rootFlags.Quiet || jsonOutput,
@@ -124,25 +94,31 @@ func newRemoteInfoCommand() *cobra.Command {
 				Invokes: []fx.Option{
 					fx.Invoke(func(v *vaultik.Vaultik, lc fx.Lifecycle) {
 						lc.Append(fx.Hook{
-							OnStart: func(ctx context.Context) error {
+							OnStart: func(_ context.Context) error {
 								go func() {
-									if err := v.RemoteInfo(jsonOutput); err != nil {
-										if err != context.Canceled {
+									err := v.RemoteInfo(jsonOutput)
+									if err != nil {
+										if !errors.Is(err, context.Canceled) {
 											if !jsonOutput {
 												log.Error("Failed to get remote info", "error", err)
-												ReportError("Failed to get remote info: %v", err)
+												ReportErrorf("Failed to get remote info: %v", err)
 											}
+
 											os.Exit(1)
 										}
 									}
-									if err := v.Shutdowner.Shutdown(); err != nil {
+
+									err = v.Shutdowner.Shutdown()
+									if err != nil {
 										log.Error("Failed to shutdown", "error", err)
 									}
 								}()
+
 								return nil
 							},
-							OnStop: func(ctx context.Context) error {
+							OnStop: func(_ context.Context) error {
 								v.Cancel()
+
 								return nil
 							},
 						})

internal/cli/root.go

@@ -1,6 +1,7 @@
 package cli
 
 import (
+	"errors"
 	"fmt"
 	"os"
 	"path/filepath"
@@ -10,6 +11,9 @@ import (
 	"github.com/spf13/cobra"
 )
 
+// errConfigNotFound is wrapped by all config-resolution failures.
+var errConfigNotFound = errors.New("config file not found")
+
 // RootFlags holds global flags that apply to all commands.
 // These flags are defined on the root command and inherited by all subcommands.
 type RootFlags struct {
@@ -20,6 +24,7 @@ type RootFlags struct {
 	SkipErrors bool
 }
 
+//nolint:gochecknoglobals // cobra persistent flags bind to package state
 var rootFlags RootFlags
 
 // NewRootCommand creates the root cobra command for the vaultik CLI.
@@ -34,20 +39,26 @@ public keys and uploads to S3-compatible storage. No private keys are needed
 on the source system.`,
 		SilenceUsage: true,
 		// Bare 'vaultik' (no subcommand): print help. The banner is
-		// printed once at process startup by CLIEntry, before cobra
+		// printed once at process startup by Entry, before cobra
 		// parses arguments, so it appears even when cobra rejects
 		// args (e.g. "requires at least 2 arg(s)") and on --help.
-		Run: func(cmd *cobra.Command, args []string) {
+		Run: func(cmd *cobra.Command, _ []string) {
 			_ = cmd.Help()
 		},
 	}
 
 	// Add global flags
-	cmd.PersistentFlags().StringVar(&rootFlags.ConfigPath, "config", "", "Path to config file (default: $VAULTIK_CONFIG or platform config dir)")
-	cmd.PersistentFlags().BoolVarP(&rootFlags.Verbose, "verbose", "v", false, "Enable verbose output")
-	cmd.PersistentFlags().BoolVar(&rootFlags.Debug, "debug", false, "Enable debug output")
-	cmd.PersistentFlags().BoolVarP(&rootFlags.Quiet, "quiet", "q", false, "Suppress non-error output")
-	cmd.PersistentFlags().BoolVar(&rootFlags.SkipErrors, "skip-errors", false, "Continue past per-file errors instead of aborting (applies to snapshot create and restore)")
+	cmd.PersistentFlags().StringVar(&rootFlags.ConfigPath, "config", "",
+		"Path to config file (default: $VAULTIK_CONFIG or platform config dir)")
+	cmd.PersistentFlags().BoolVarP(&rootFlags.Verbose, "verbose", "v", false,
+		"Enable verbose output")
+	cmd.PersistentFlags().BoolVar(&rootFlags.Debug, "debug", false,
+		"Enable debug output")
+	cmd.PersistentFlags().BoolVarP(&rootFlags.Quiet, "quiet", "q", false,
+		"Suppress non-error output")
+	cmd.PersistentFlags().BoolVar(&rootFlags.SkipErrors, "skip-errors", false,
+		"Continue past per-file errors instead of aborting "+
+			"(applies to snapshot create and restore)")
 
 	// Add subcommands
 	cmd.AddCommand(
@@ -70,31 +81,45 @@ func GetRootFlags() RootFlags {
 }
 
 // ResolveConfigPath resolves the config file path from flags, environment, or default.
-// Search order: --config flag, VAULTIK_CONFIG env, XDG config dir, /etc/vaultik/config.yml.
+// Search order: --config flag, VAULTIK_CONFIG env, XDG config dir,
+// /etc/vaultik/config.yml.
 // Explicit paths from --config and $VAULTIK_CONFIG are checked for existence
 // so the user gets a clear error instead of a downstream YAML parser failure.
 func ResolveConfigPath() (string, error) {
 	if path := rootFlags.ConfigPath; path != "" {
-		if _, err := os.Stat(path); err != nil {
-			return "", fmt.Errorf("config file from --config not found: %s (run 'vaultik config init --config %s' to create it)", path, path)
+		_, err := os.Stat(path)
+		if err != nil {
+			return "", fmt.Errorf(
+				"%w: from --config: %s (run 'vaultik config init --config %s' to create it)",
+				errConfigNotFound, path, path)
 		}
+
 		return path, nil
 	}
 
 	if path := os.Getenv("VAULTIK_CONFIG"); path != "" {
-		if _, err := os.Stat(path); err != nil {
-			return "", fmt.Errorf("config file from $VAULTIK_CONFIG not found: %s (unset VAULTIK_CONFIG, point it at an existing file, or run 'vaultik config init')", path)
+		_, err := os.Stat(path) //nolint:gosec // G703: path is operator-supplied by design
+		if err != nil {
+			return "", fmt.Errorf(
+				"%w: from $VAULTIK_CONFIG: %s (unset VAULTIK_CONFIG, point it at "+
+					"an existing file, or run 'vaultik config init')",
+				errConfigNotFound, path)
 		}
+
 		return path, nil
 	}
 
 	for _, path := range defaultConfigPaths() {
-		if _, err := os.Stat(path); err == nil {
+		_, err := os.Stat(path)
+		if err == nil {
 			return path, nil
 		}
 	}
 
-	return "", fmt.Errorf("no config file found at %s (run 'vaultik config init' to create the default config, or pass --config <path>)", strings.Join(defaultConfigPaths(), " or "))
+	return "", fmt.Errorf(
+		"%w: searched %s (run 'vaultik config init' to create the default "+
+			"config, or pass --config <path>)",
+		errConfigNotFound, strings.Join(defaultConfigPaths(), " or "))
 }
 
 // defaultConfigPaths returns the ordered list of config paths to search.
@@ -114,5 +139,6 @@ func DefaultConfigPath() string {
 	if os.Getuid() == 0 {
 		return "/etc/vaultik/config.yml"
 	}
+
 	return filepath.Join(xdg.ConfigHome, "vaultik", "config.yml")
 }

internal/cli/snapshot.go

@@ -2,6 +2,7 @@ package cli
 
 import (
 	"context"
+	"errors"
 	"fmt"
 	"os"
 
@@ -11,6 +12,32 @@ import (
 	"sneak.berlin/go/vaultik/internal/vaultik"
 )
 
+var (
+	errSnapshotIDRequired  = errors.New("snapshot ID required")
+	errWrongArgCount       = errors.New("wrong argument count")
+	errPurgeCriteriaNeeded = errors.New(
+		"must specify either --keep-latest or --older-than")
+	errPurgeCriteriaBoth = errors.New(
+		"cannot specify both --keep-latest and --older-than")
+)
+
+// requireSnapshotIDArg validates that exactly one positional argument
+// (the snapshot ID) was supplied, printing help otherwise.
+func requireSnapshotIDArg(cmd *cobra.Command, args []string) error {
+	if len(args) != 1 {
+		_ = cmd.Help()
+
+		if len(args) == 0 {
+			return errSnapshotIDRequired
+		}
+
+		return fmt.Errorf("%w: expected 1 argument, got %d",
+			errWrongArgCount, len(args))
+	}
+
+	return nil
+}
+
 // NewSnapshotCommand creates the snapshot command and subcommands
 func NewSnapshotCommand() *cobra.Command {
 	cmd := &cobra.Command{
@@ -58,9 +85,10 @@ specifying a path using --config or by setting VAULTIK_CONFIG to a path.`,
 
 			// Use the backup functionality from cli package
 			rootFlags := GetRootFlags()
+
 			return RunWithApp(cmd.Context(), AppOptions{
 				ConfigPath: configPath,
-				LogOptions: log.LogOptions{
+				LogOptions: log.Options{
 					Verbose: rootFlags.Verbose,
 					Debug:   rootFlags.Debug,
 					Cron:    opts.Cron,
@@ -70,29 +98,33 @@ specifying a path using --config or by setting VAULTIK_CONFIG to a path.`,
 				Invokes: []fx.Option{
 					fx.Invoke(func(v *vaultik.Vaultik, lc fx.Lifecycle) {
 						lc.Append(fx.Hook{
-							OnStart: func(ctx context.Context) error {
+							OnStart: func(_ context.Context) error {
 								// Start the snapshot creation in a goroutine
 								go func() {
 									// --cron suppression is wired through v.UI by setupGlobals.
-									if err := v.CreateSnapshot(opts); err != nil {
-										if err != context.Canceled {
+									err := v.CreateSnapshot(opts)
+									if err != nil {
+										if !errors.Is(err, context.Canceled) {
 											log.Error("Snapshot creation failed", "error", err)
-											ReportError("Snapshot creation failed: %v", err)
+											ReportErrorf("Snapshot creation failed: %v", err)
 											os.Exit(1)
 										}
 									}
 
 									// Shutdown the app when snapshot completes
-									if err := v.Shutdowner.Shutdown(); err != nil {
+									err = v.Shutdowner.Shutdown()
+									if err != nil {
 										log.Error("Failed to shutdown", "error", err)
 									}
 								}()
+
 								return nil
 							},
-							OnStop: func(ctx context.Context) error {
+							OnStop: func(_ context.Context) error {
 								log.Debug("Stopping snapshot creation")
 								// Cancel the Vaultik context
 								v.Cancel()
+
 								return nil
 							},
 						})
@@ -102,9 +134,14 @@ specifying a path using --config or by setting VAULTIK_CONFIG to a path.`,
 		},
 	}
 
-	cmd.Flags().BoolVar(&opts.Cron, "cron", false, "Run in cron mode (silent unless error)")
-	cmd.Flags().BoolVar(&opts.Prune, "prune", false, "After backup, drop older snapshots of the same name and remove orphaned blobs")
-	cmd.Flags().StringVar(&opts.KeepNewerThan, "keep-newer-than", "", "With --prune: keep snapshots newer than this duration (e.g. 4w, 30d, 6mo) instead of only the latest")
+	cmd.Flags().BoolVar(&opts.Cron, "cron", false,
+		"Run in cron mode (silent unless error)")
+	cmd.Flags().BoolVar(&opts.Prune, "prune", false,
+		"After backup, drop older snapshots of the same name and remove "+
+			"orphaned blobs")
+	cmd.Flags().StringVar(&opts.KeepNewerThan, "keep-newer-than", "",
+		"With --prune: keep snapshots newer than this duration "+
+			"(e.g. 4w, 30d, 6mo) instead of only the latest")
 
 	return cmd
 }
@@ -119,47 +156,11 @@ func newSnapshotListCommand() *cobra.Command {
 		Short:   "List all snapshots",
 		Long:    "Lists all snapshots with their ID, timestamp, and compressed size",
 		Args:    cobra.NoArgs,
-		RunE: func(cmd *cobra.Command, args []string) error {
-			// Use unified config resolution
-			configPath, err := ResolveConfigPath()
-			if err != nil {
-				return err
-			}
-
-			rootFlags := GetRootFlags()
-			return RunWithApp(cmd.Context(), AppOptions{
-				ConfigPath: configPath,
-				LogOptions: log.LogOptions{
-					Verbose: rootFlags.Verbose,
-					Debug:   rootFlags.Debug,
-					Quiet:   rootFlags.Quiet,
-				},
-				Modules: []fx.Option{},
-				Invokes: []fx.Option{
-					fx.Invoke(func(v *vaultik.Vaultik, lc fx.Lifecycle) {
-						lc.Append(fx.Hook{
-							OnStart: func(ctx context.Context) error {
-								go func() {
-									if err := v.ListSnapshots(jsonOutput); err != nil {
-										if err != context.Canceled {
-											log.Error("Failed to list snapshots", "error", err)
-											ReportError("Failed to list snapshots: %v", err)
-											os.Exit(1)
-										}
-									}
-									if err := v.Shutdowner.Shutdown(); err != nil {
-										log.Error("Failed to shutdown", "error", err)
-									}
-								}()
-								return nil
-							},
-							OnStop: func(ctx context.Context) error {
-								v.Cancel()
-								return nil
-							},
-						})
-					}),
-				},
+		RunE: func(cmd *cobra.Command, _ []string) error {
+			return runVaultikApp(cmd, false, false,
+				"Failed to list snapshots",
+				func(v *vaultik.Vaultik) error {
+					return v.ListSnapshots(jsonOutput)
 				})
 		},
 	}
@@ -182,63 +183,31 @@ Retention is per-snapshot-name: --keep-latest keeps the latest of each
 configured snapshot name, not the latest globally. Use --snapshot to
 restrict the operation to specific snapshot names.`,
 		Args: cobra.NoArgs,
-		RunE: func(cmd *cobra.Command, args []string) error {
+		RunE: func(cmd *cobra.Command, _ []string) error {
 			// Validate flags
 			if !opts.KeepLatest && opts.OlderThan == "" {
-				return fmt.Errorf("must specify either --keep-latest or --older-than")
+				return errPurgeCriteriaNeeded
 			}
+
 			if opts.KeepLatest && opts.OlderThan != "" {
-				return fmt.Errorf("cannot specify both --keep-latest and --older-than")
+				return errPurgeCriteriaBoth
 			}
 
-			// Use unified config resolution
-			configPath, err := ResolveConfigPath()
-			if err != nil {
-				return err
-			}
-
-			rootFlags := GetRootFlags()
-			return RunWithApp(cmd.Context(), AppOptions{
-				ConfigPath: configPath,
-				LogOptions: log.LogOptions{
-					Verbose: rootFlags.Verbose,
-					Debug:   rootFlags.Debug,
-					Quiet:   rootFlags.Quiet,
-				},
-				Modules: []fx.Option{},
-				Invokes: []fx.Option{
-					fx.Invoke(func(v *vaultik.Vaultik, lc fx.Lifecycle) {
-						lc.Append(fx.Hook{
-							OnStart: func(ctx context.Context) error {
-								go func() {
-									if err := v.PurgeSnapshotsWithOptions(opts); err != nil {
-										if err != context.Canceled {
-											log.Error("Failed to purge snapshots", "error", err)
-											ReportError("Failed to purge snapshots: %v", err)
-											os.Exit(1)
-										}
-									}
-									if err := v.Shutdowner.Shutdown(); err != nil {
-										log.Error("Failed to shutdown", "error", err)
-									}
-								}()
-								return nil
-							},
-							OnStop: func(ctx context.Context) error {
-								v.Cancel()
-								return nil
-							},
-						})
-					}),
-				},
+			return runVaultikApp(cmd, false, false,
+				"Failed to purge snapshots",
+				func(v *vaultik.Vaultik) error {
+					return v.PurgeSnapshotsWithOptions(opts)
 				})
 		},
 	}
 
-	cmd.Flags().BoolVar(&opts.KeepLatest, "keep-latest", false, "Keep only the latest snapshot of each name")
-	cmd.Flags().StringVar(&opts.OlderThan, "older-than", "", "Remove snapshots older than duration (e.g., 30d, 6m, 1y)")
+	cmd.Flags().BoolVar(&opts.KeepLatest, "keep-latest", false,
+		"Keep only the latest snapshot of each name")
+	cmd.Flags().StringVar(&opts.OlderThan, "older-than", "",
+		"Remove snapshots older than duration (e.g., 30d, 6m, 1y)")
 	cmd.Flags().BoolVar(&opts.Force, "force", false, "Skip confirmation prompt")
-	cmd.Flags().StringArrayVar(&opts.Names, "snapshot", nil, "Restrict to snapshots with these names (repeat for multiple)")
+	cmd.Flags().StringArrayVar(&opts.Names, "snapshot", nil,
+		"Restrict to snapshots with these names (repeat for multiple)")
 
 	return cmd
 }
@@ -251,16 +220,7 @@ func newSnapshotVerifyCommand() *cobra.Command {
 		Use:   "verify <snapshot-id>",
 		Short: "Verify snapshot integrity",
 		Long:  "Verifies that all blobs referenced in a snapshot exist",
-		Args: func(cmd *cobra.Command, args []string) error {
-			if len(args) != 1 {
-				_ = cmd.Help()
-				if len(args) == 0 {
-					return fmt.Errorf("snapshot ID required")
-				}
-				return fmt.Errorf("expected 1 argument, got %d", len(args))
-			}
-			return nil
-		},
+		Args:  requireSnapshotIDArg,
 		RunE: func(cmd *cobra.Command, args []string) error {
 			snapshotID := args[0]
 
@@ -271,9 +231,10 @@ func newSnapshotVerifyCommand() *cobra.Command {
 			}
 
 			rootFlags := GetRootFlags()
+
 			return RunWithApp(cmd.Context(), AppOptions{
 				ConfigPath: configPath,
-				LogOptions: log.LogOptions{
+				LogOptions: log.Options{
 					Verbose: rootFlags.Verbose,
 					Debug:   rootFlags.Debug,
 					Quiet:   rootFlags.Quiet || opts.JSON,
@@ -282,25 +243,31 @@ func newSnapshotVerifyCommand() *cobra.Command {
 				Invokes: []fx.Option{
 					fx.Invoke(func(v *vaultik.Vaultik, lc fx.Lifecycle) {
 						lc.Append(fx.Hook{
-							OnStart: func(ctx context.Context) error {
+							OnStart: func(_ context.Context) error {
 								go func() {
-									if err := v.VerifySnapshotWithOptions(snapshotID, opts); err != nil {
-										if err != context.Canceled {
+									err := v.VerifySnapshotWithOptions(snapshotID, opts)
+									if err != nil {
+										if !errors.Is(err, context.Canceled) {
 											if !opts.JSON {
 												log.Error("Verification failed", "error", err)
-												ReportError("Verification failed: %v", err)
+												ReportErrorf("Verification failed: %v", err)
 											}
+
 											os.Exit(1)
 										}
 									}
-									if err := v.Shutdowner.Shutdown(); err != nil {
+
+									err = v.Shutdowner.Shutdown()
+									if err != nil {
 										log.Error("Failed to shutdown", "error", err)
 									}
 								}()
+
 								return nil
 							},
-							OnStop: func(ctx context.Context) error {
+							OnStop: func(_ context.Context) error {
 								v.Cancel()
+
 								return nil
 							},
 						})
@@ -342,68 +309,24 @@ is reachable to finish remote cleanup.
 
 To wipe the entire destination store and start over, use 'vaultik remote
 nuke --force' — it is the single supported entry point for that.`,
-		Args: func(cmd *cobra.Command, args []string) error {
-			if len(args) != 1 {
-				_ = cmd.Help()
-				if len(args) == 0 {
-					return fmt.Errorf("snapshot ID required")
-				}
-				return fmt.Errorf("expected 1 argument, got %d", len(args))
-			}
-			return nil
-		},
+		Args: requireSnapshotIDArg,
 		RunE: func(cmd *cobra.Command, args []string) error {
-			// Use unified config resolution
-			configPath, err := ResolveConfigPath()
-			if err != nil {
-				return err
-			}
-
-			rootFlags := GetRootFlags()
-			return RunWithApp(cmd.Context(), AppOptions{
-				ConfigPath: configPath,
-				LogOptions: log.LogOptions{
-					Verbose: rootFlags.Verbose,
-					Debug:   rootFlags.Debug,
-					Quiet:   rootFlags.Quiet || opts.JSON,
-				},
-				Modules: []fx.Option{},
-				Invokes: []fx.Option{
-					fx.Invoke(func(v *vaultik.Vaultik, lc fx.Lifecycle) {
-						lc.Append(fx.Hook{
-							OnStart: func(ctx context.Context) error {
-								go func() {
+			return runVaultikApp(cmd, opts.JSON, opts.JSON,
+				"Failed to remove snapshot",
+				func(v *vaultik.Vaultik) error {
 					_, err := v.RemoveSnapshot(args[0], opts)
-									if err != nil {
-										if err != context.Canceled {
-											if !opts.JSON {
-												log.Error("Failed to remove snapshot", "error", err)
-												ReportError("Failed to remove snapshot: %v", err)
-											}
-											os.Exit(1)
-										}
-									}
-									if err := v.Shutdowner.Shutdown(); err != nil {
-										log.Error("Failed to shutdown", "error", err)
-									}
-								}()
-								return nil
-							},
-							OnStop: func(ctx context.Context) error {
-								v.Cancel()
-								return nil
-							},
-						})
-					}),
-				},
+
+					return err
 				})
 		},
 	}
 
 	cmd.Flags().BoolVarP(&opts.Force, "force", "f", false, "Skip confirmation prompt")
-	cmd.Flags().BoolVar(&opts.DryRun, "dry-run", false, "Show what would be removed without removing")
+	cmd.Flags().BoolVar(&opts.DryRun, "dry-run", false,
+		"Show what would be removed without removing")
 	cmd.Flags().BoolVar(&opts.JSON, "json", false, "Output result as JSON")
-	cmd.Flags().BoolVar(&opts.LocalOnly, "local-only", false, "Skip remote cleanup; only touch the local index")
+	cmd.Flags().BoolVar(&opts.LocalOnly, "local-only", false,
+		"Skip remote cleanup; only touch the local index")
 
 	return cmd
 }

internal/cli/snapshot_restore.go

@@ -2,6 +2,7 @@ package cli
 
 import (
 	"context"
+	"errors"
 	"os"
 
 	"github.com/spf13/cobra"
@@ -13,6 +14,10 @@ import (
 	"sneak.berlin/go/vaultik/internal/vaultik"
 )
 
+// restoreMinArgs is the minimum positional argument count of
+// `snapshot restore <snapshot-id> <target-dir> [paths...]`.
+const restoreMinArgs = 2
+
 // RestoreOptions contains options for the restore command
 type RestoreOptions struct {
 	TargetDir string
@@ -38,31 +43,36 @@ func newSnapshotRestoreCommand() *cobra.Command {
 		Short: "Restore files from a snapshot",
 		Long: `Download and decrypt files from a backup snapshot.
 
-This command will restore files from the specified snapshot to the target directory.
+This command will restore files from the specified snapshot to the
+target directory.
 If no paths are specified, all files are restored.
 If paths are specified, only matching files/directories are restored.
 
-Requires the VAULTIK_AGE_SECRET_KEY environment variable to be set with the age private key.
+Requires the VAULTIK_AGE_SECRET_KEY environment variable to be set with
+the age private key.
 
 Examples:
   # Restore entire snapshot
   vaultik snapshot restore myhost_docs_2025-01-01T12:00:00Z /restore
 
   # Restore specific file
-  vaultik snapshot restore myhost_docs_2025-01-01T12:00:00Z /restore /home/user/important.txt
+  vaultik snapshot restore myhost_docs_2025-01-01T12:00:00Z /restore \
+    /home/user/important.txt
 
   # Restore specific directory
-  vaultik snapshot restore myhost_docs_2025-01-01T12:00:00Z /restore /home/user/documents/
+  vaultik snapshot restore myhost_docs_2025-01-01T12:00:00Z /restore \
+    /home/user/documents/
 
   # Restore and verify all files
   vaultik snapshot restore --verify myhost_docs_2025-01-01T12:00:00Z /restore`,
-		Args: cobra.MinimumNArgs(2),
+		Args: cobra.MinimumNArgs(restoreMinArgs),
 		RunE: func(cmd *cobra.Command, args []string) error {
 			return runRestore(cmd, args, opts)
 		},
 	}
 
-	cmd.Flags().BoolVar(&opts.Verify, "verify", false, "Verify restored files by checking chunk hashes")
+	cmd.Flags().BoolVar(&opts.Verify, "verify", false,
+		"Verify restored files by checking chunk hashes")
 
 	return cmd
 }
@@ -70,9 +80,10 @@ Examples:
 // runRestore parses arguments and runs the restore operation through the app framework
 func runRestore(cmd *cobra.Command, args []string, opts *RestoreOptions) error {
 	snapshotID := args[0]
+
 	opts.TargetDir = args[1]
-	if len(args) > 2 {
-		opts.Paths = args[2:]
+	if len(args) > restoreMinArgs {
+		opts.Paths = args[restoreMinArgs:]
 	}
 
 	// Use unified config resolution
@@ -83,9 +94,10 @@ func runRestore(cmd *cobra.Command, args []string, opts *RestoreOptions) error {
 
 	// Use the app framework like other commands
 	rootFlags := GetRootFlags()
+
 	return RunWithApp(cmd.Context(), AppOptions{
 		ConfigPath: configPath,
-		LogOptions: log.LogOptions{
+		LogOptions: log.Options{
 			Verbose: rootFlags.Verbose,
 			Debug:   rootFlags.Debug,
 			Quiet:   rootFlags.Quiet,
@@ -118,7 +130,7 @@ func buildRestoreInvokes(snapshotID string, opts *RestoreOptions) []fx.Option {
 	return []fx.Option{
 		fx.Invoke(func(app *RestoreApp, lc fx.Lifecycle) {
 			lc.Append(fx.Hook{
-				OnStart: func(ctx context.Context) error {
+				OnStart: func(_ context.Context) error {
 					// Start the restore operation in a goroutine
 					go func() {
 						// Run the restore operation
@@ -129,24 +141,29 @@ func buildRestoreInvokes(snapshotID string, opts *RestoreOptions) []fx.Option {
 							Verify:     opts.Verify,
 							SkipErrors: GetRootFlags().SkipErrors,
 						}
-						if err := app.Vaultik.Restore(restoreOpts); err != nil {
-							if err != context.Canceled {
+
+						err := app.Vaultik.Restore(restoreOpts)
+						if err != nil {
+							if !errors.Is(err, context.Canceled) {
 								log.Error("Restore operation failed", "error", err)
-								ReportError("Restore failed: %v", err)
+								ReportErrorf("Restore failed: %v", err)
 								os.Exit(1)
 							}
 						}
 
 						// Shutdown the app when restore completes
-						if err := app.Shutdowner.Shutdown(); err != nil {
+						err = app.Shutdowner.Shutdown()
+						if err != nil {
 							log.Error("Failed to shutdown", "error", err)
 						}
 					}()
+
 					return nil
 				},
-				OnStop: func(ctx context.Context) error {
+				OnStop: func(_ context.Context) error {
 					log.Debug("Stopping restore operation")
 					app.Vaultik.Cancel()
+
 					return nil
 				},
 			})

internal/cli/vaultik_snapshot_types.go

@@ -3,6 +3,8 @@ package cli
 import "time"
 
 // SnapshotInfo represents snapshot information for listing
+//
+//nolint:tagliatelle // snake_case is the established output format
 type SnapshotInfo struct {
 	ID             string    `json:"id"`
 	Timestamp      time.Time `json:"timestamp"`

internal/cli/version.go

@@ -2,6 +2,7 @@ package cli
 
 import (
 	"fmt"
+	"os"
 	"runtime"
 
 	"github.com/spf13/cobra"
@@ -15,20 +16,25 @@ func NewVersionCommand() *cobra.Command {
 		Short: "Print version information",
 		Long:  `Print version, git commit, and build information for vaultik.`,
 		Args:  cobra.NoArgs,
-		Run: func(cmd *cobra.Command, args []string) {
-			fmt.Printf("vaultik %s\n", globals.Version)
-			fmt.Printf("  commit:     %s\n", globals.Commit)
-			fmt.Printf("  build date: %s\n", globals.CommitDate)
-			fmt.Printf("  go:         %s\n", runtime.Version())
-			fmt.Printf("  os/arch:    %s/%s\n", runtime.GOOS, runtime.GOARCH)
-			fmt.Printf("  author:     %s\n", globals.Author)
-			fmt.Printf("  homepage:   %s\n", globals.Homepage)
-			fmt.Printf("  license:    %s\n", globals.License)
+		Run: func(_ *cobra.Command, _ []string) {
+			_, _ = fmt.Fprintf(os.Stdout, "vaultik %s\n", globals.Version)
+			_, _ = fmt.Fprintf(os.Stdout, "  commit:     %s\n", globals.Commit)
+			_, _ = fmt.Fprintf(os.Stdout, "  build date: %s\n", globals.CommitDate)
+			_, _ = fmt.Fprintf(os.Stdout, "  go:         %s\n", runtime.Version())
+			_, _ = fmt.Fprintf(os.Stdout, "  os/arch:    %s/%s\n",
+				runtime.GOOS, runtime.GOARCH)
+			_, _ = fmt.Fprintf(os.Stdout, "  author:     %s\n", globals.Author)
+			_, _ = fmt.Fprintf(os.Stdout, "  homepage:   %s\n", globals.Homepage)
+			_, _ = fmt.Fprintf(os.Stdout, "  license:    %s\n", globals.License)
+
 			if globals.Version == "dev" {
-				fmt.Println()
-				fmt.Println("This is a development build (no version information embedded).")
-				fmt.Println("Build a release binary with 'make vaultik' or download from")
-				fmt.Println("https://sneak.berlin/go/vaultik for embedded version metadata.")
+				_, _ = fmt.Fprintln(os.Stdout)
+				_, _ = fmt.Fprintln(os.Stdout,
+					"This is a development build (no version information embedded).")
+				_, _ = fmt.Fprintln(os.Stdout,
+					"Build a release binary with 'make vaultik' or download from")
+				_, _ = fmt.Fprintln(os.Stdout,
+					"https://sneak.berlin/go/vaultik for embedded version metadata.")
 			}
 		},
 	}

internal/config/config.go

@@ -1,6 +1,10 @@
+// Package config loads, validates, and provides the vaultik YAML
+// configuration, including snapshot definitions, encryption recipients,
+// and storage settings.
 package config
 
 import (
+	"errors"
 	"fmt"
 	"os"
 	"path/filepath"
@@ -17,16 +21,52 @@ import (
 
 const appName = "vaultik"
 
+// Defaults and validation bounds for tunable settings.
+const (
+	defaultBlobSizeLimit    = Size(10 * 1024 * 1024 * 1024) // 10GB
+	defaultChunkSize        = Size(10 * 1024 * 1024)        // 10MB
+	defaultS3PartSize       = Size(5 * 1024 * 1024)         // 5MB
+	defaultCompressionLevel = 3
+	minChunkSize            = 1024 * 1024 // 1MB
+	minCompressionLevel     = 1
+	maxCompressionLevel     = 19
+)
+
+// Sentinel validation errors.
+var (
+	errNoConfigPath    = errors.New("config path not provided")
+	errNoAgeRecipients = errors.New(
+		"at least one age_recipient is required (generate with: age-keygen)")
+	errNoSnapshots = errors.New(
+		"at least one snapshot must be configured (see config.example.yml)")
+	errSnapshotNoPaths   = errors.New("snapshot must have at least one path")
+	errChunkSizeTooSmall = errors.New("chunk_size must be at least 1MB")
+	errBlobSizeTooSmall  = errors.New("blob_size_limit must be at least chunk_size")
+	errBadCompression    = errors.New("compression_level must be between 1 and 19")
+	errBadStorageScheme  = errors.New(
+		"storage_url must start with s3://, file://, or rclone://")
+	errStorageNotConfigured = errors.New(
+		"storage not configured; set storage_url or provide s3.endpoint + " +
+			"s3.bucket + credentials")
+	errS3BucketRequired = errors.New("s3.bucket is required (or set storage_url)")
+	errS3KeyIDRequired  = errors.New("s3.access_key_id is required")
+	errS3SecretRequired = errors.New("s3.secret_access_key is required")
+)
+
 // expandTilde expands ~ at the start of a path to the user's home directory.
 func expandTilde(path string) string {
 	if path == "~" {
 		home, _ := os.UserHomeDir()
+
 		return home
 	}
+
 	if strings.HasPrefix(path, "~/") {
 		home, _ := os.UserHomeDir()
+
 		return filepath.Join(home, path[2:])
 	}
+
 	return path
 }
 
@@ -34,8 +74,10 @@ func expandTilde(path string) string {
 func expandTildeInURL(url string) string {
 	if strings.HasPrefix(url, "file://~/") {
 		home, _ := os.UserHomeDir()
+
 		return "file://" + filepath.Join(home, url[9:])
 	}
+
 	return url
 }
 
@@ -63,6 +105,7 @@ func (c *Config) GetExcludes(snapshotName string) []string {
 	combined := make([]string, 0, len(c.Exclude)+len(snap.Exclude))
 	combined = append(combined, c.Exclude...)
 	combined = append(combined, snap.Exclude...)
+
 	return combined
 }
 
@@ -74,6 +117,7 @@ func (c *Config) SnapshotNames() []string {
 	}
 	// Sort for deterministic order
 	sort.Strings(names)
+
 	return names
 }
 
@@ -81,12 +125,15 @@ func (c *Config) SnapshotNames() []string {
 // It defines all settings for backup operations, including source directories,
 // encryption recipients, storage configuration, and performance tuning parameters.
 // Configuration is typically loaded from a YAML file.
+//
+//nolint:tagliatelle // snake_case is the established config-file format
 type Config struct {
 	AgeRecipients []string `yaml:"age_recipients"`
 	AgeSecretKey  string   `yaml:"age_secret_key"`
 	BlobSizeLimit Size     `yaml:"blob_size_limit"`
 	ChunkSize     Size     `yaml:"chunk_size"`
-	Exclude          []string                  `yaml:"exclude"` // Global excludes applied to all snapshots
+	// Exclude holds global excludes applied to all snapshots.
+	Exclude          []string                  `yaml:"exclude"`
 	Hostname         string                    `yaml:"hostname"`
 	IndexPath        string                    `yaml:"index_path"`
 	S3               S3Config                  `yaml:"s3"`
@@ -98,13 +145,16 @@ type Config struct {
 	// Supported formats:
 	//   - s3://bucket/prefix?endpoint=host&region=us-east-1
 	//   - file:///path/to/backup
-	// For S3 URLs, credentials are still read from s3.access_key_id and s3.secret_access_key.
+	// For S3 URLs, credentials are still read from s3.access_key_id
+	// and s3.secret_access_key.
 	StorageURL string `yaml:"storage_url"`
 }
 
 // S3Config represents S3 storage configuration for backup storage.
 // It supports both AWS S3 and S3-compatible storage services.
 // All fields except UseSSL and PartSize are required.
+//
+//nolint:tagliatelle // snake_case is the established config-file format
 type S3Config struct {
 	Endpoint        string `yaml:"endpoint"`
 	Bucket          string `yaml:"bucket"`
@@ -116,17 +166,17 @@ type S3Config struct {
 	PartSize        Size   `yaml:"part_size"`
 }
 
-// ConfigPath wraps the config file path for fx dependency injection.
+// Path wraps the config file path for fx dependency injection.
 // This type allows the config file path to be injected as a distinct type
 // rather than a plain string, avoiding conflicts with other string dependencies.
-type ConfigPath string
+type Path string
 
 // New creates a new Config instance by loading from the specified path.
 // This function is used by the fx dependency injection framework.
 // Returns an error if the path is empty or if loading fails.
-func New(path ConfigPath) (*Config, error) {
+func New(path Path) (*Config, error) {
 	if path == "" {
-		return nil, fmt.Errorf("config path not provided")
+		return nil, errNoConfigPath
 	}
 
 	cfg, err := Load(string(path))
@@ -151,20 +201,22 @@ func Load(path string) (*Config, error) {
 
 	cfg := &Config{
 		// Set defaults
-		BlobSizeLimit:    Size(10 * 1024 * 1024 * 1024), // 10GB
-		ChunkSize:        Size(10 * 1024 * 1024),        // 10MB
+		BlobSizeLimit:    defaultBlobSizeLimit,
+		ChunkSize:        defaultChunkSize,
 		IndexPath:        filepath.Join(xdg.DataHome, appName, "index.sqlite"),
-		CompressionLevel: 3,
+		CompressionLevel: defaultCompressionLevel,
 	}
 
 	// Convert smartconfig data to YAML then unmarshal
 	configData := sc.Data()
+
 	yamlBytes, err := yaml.Marshal(configData)
 	if err != nil {
 		return nil, fmt.Errorf("failed to marshal config data: %w", err)
 	}
 
-	if err := yaml.Unmarshal(yamlBytes, cfg); err != nil {
+	err = yaml.Unmarshal(yamlBytes, cfg)
+	if err != nil {
 		return nil, fmt.Errorf("failed to parse config: %w", err)
 	}
 
@@ -177,6 +229,7 @@ func Load(path string) (*Config, error) {
 		for i, path := range snap.Paths {
 			snap.Paths[i] = expandTilde(path)
 		}
+
 		cfg.Snapshots[name] = snap
 	}
 
@@ -196,6 +249,7 @@ func Load(path string) (*Config, error) {
 		if err != nil {
 			return nil, fmt.Errorf("failed to get hostname: %w", err)
 		}
+
 		cfg.Hostname = hostname
 	}
 
@@ -203,12 +257,15 @@ func Load(path string) (*Config, error) {
 	if cfg.S3.Region == "" {
 		cfg.S3.Region = "us-east-1"
 	}
+
 	if cfg.S3.PartSize == 0 {
-		cfg.S3.PartSize = Size(5 * 1024 * 1024) // 5MB
+		cfg.S3.PartSize = defaultS3PartSize
 	}
 
 	// Check config file permissions (warn if world or group readable)
-	if info, err := os.Stat(path); err == nil {
+	//nolint:gosec // G703: config path is operator-supplied by design
+	info, statErr := os.Stat(path)
+	if statErr == nil {
 		mode := info.Mode().Perm()
 		if mode&0044 != 0 { // group or world readable
 			log.Warn("Config file has insecure permissions (contains S3 credentials)",
@@ -218,7 +275,8 @@ func Load(path string) (*Config, error) {
 		}
 	}
 
-	if err := cfg.Validate(); err != nil {
+	err = cfg.Validate()
+	if err != nil {
 		return nil, fmt.Errorf("invalid config: %w", err)
 	}
 
@@ -236,34 +294,36 @@ func Load(path string) (*Config, error) {
 // Returns an error describing the first validation failure encountered.
 func (c *Config) Validate() error {
 	if len(c.AgeRecipients) == 0 {
-		return fmt.Errorf("at least one age_recipient is required (generate with: age-keygen)")
+		return errNoAgeRecipients
 	}
 
 	if len(c.Snapshots) == 0 {
-		return fmt.Errorf("at least one snapshot must be configured (see config.example.yml)")
+		return errNoSnapshots
 	}
 
 	for name, snap := range c.Snapshots {
 		if len(snap.Paths) == 0 {
-			return fmt.Errorf("snapshot %q must have at least one path", name)
+			return fmt.Errorf("%w: %q", errSnapshotNoPaths, name)
 		}
 	}
 
 	// Validate storage configuration
-	if err := c.validateStorage(); err != nil {
+	err := c.validateStorage()
+	if err != nil {
 		return err
 	}
 
-	if c.ChunkSize.Int64() < 1024*1024 { // 1MB minimum
-		return fmt.Errorf("chunk_size must be at least 1MB")
+	if c.ChunkSize.Int64() < minChunkSize {
+		return errChunkSizeTooSmall
 	}
 
 	if c.BlobSizeLimit.Int64() < c.ChunkSize.Int64() {
-		return fmt.Errorf("blob_size_limit must be at least chunk_size")
+		return errBlobSizeTooSmall
 	}
 
-	if c.CompressionLevel < 1 || c.CompressionLevel > 19 {
-		return fmt.Errorf("compression_level must be between 1 and 19")
+	if c.CompressionLevel < minCompressionLevel ||
+		c.CompressionLevel > maxCompressionLevel {
+		return errBadCompression
 	}
 
 	return nil
@@ -275,48 +335,56 @@ func (c *Config) Validate() error {
 // If StorageURL is not set, legacy S3 configuration is required.
 func (c *Config) validateStorage() error {
 	if c.StorageURL != "" {
-		// URL-based configuration
-		if strings.HasPrefix(c.StorageURL, "file://") {
-			// File storage doesn't need S3 credentials
-			return nil
-		}
-		if strings.HasPrefix(c.StorageURL, "s3://") {
-			// S3 storage needs credentials
-			if c.S3.AccessKeyID == "" {
-				return fmt.Errorf("s3.access_key_id is required for s3:// URLs")
-			}
-			if c.S3.SecretAccessKey == "" {
-				return fmt.Errorf("s3.secret_access_key is required for s3:// URLs")
-			}
-			return nil
-		}
-		if strings.HasPrefix(c.StorageURL, "rclone://") {
-			// Rclone storage uses rclone's own config
-			return nil
-		}
-		return fmt.Errorf("storage_url must start with s3://, file://, or rclone://")
+		return c.validateStorageURL()
 	}
 
 	// Legacy S3 configuration
 	if c.S3.Endpoint == "" {
-		return fmt.Errorf("storage not configured; set storage_url or provide s3.endpoint + s3.bucket + credentials")
+		return errStorageNotConfigured
 	}
 
 	if c.S3.Bucket == "" {
-		return fmt.Errorf("s3.bucket is required (or set storage_url)")
+		return errS3BucketRequired
 	}
 
 	if c.S3.AccessKeyID == "" {
-		return fmt.Errorf("s3.access_key_id is required")
+		return errS3KeyIDRequired
 	}
 
 	if c.S3.SecretAccessKey == "" {
-		return fmt.Errorf("s3.secret_access_key is required")
+		return errS3SecretRequired
 	}
 
 	return nil
 }
 
+// validateStorageURL validates URL-based storage configuration. File and
+// rclone URLs need no credentials; S3 URLs require the legacy s3.*
+// credential fields.
+func (c *Config) validateStorageURL() error {
+	switch {
+	case strings.HasPrefix(c.StorageURL, "file://"):
+		// File storage doesn't need S3 credentials
+		return nil
+	case strings.HasPrefix(c.StorageURL, "rclone://"):
+		// Rclone storage uses rclone's own config
+		return nil
+	case strings.HasPrefix(c.StorageURL, "s3://"):
+		// S3 storage needs credentials
+		if c.S3.AccessKeyID == "" {
+			return fmt.Errorf("%w for s3:// URLs", errS3KeyIDRequired)
+		}
+
+		if c.S3.SecretAccessKey == "" {
+			return fmt.Errorf("%w for s3:// URLs", errS3SecretRequired)
+		}
+
+		return nil
+	default:
+		return errBadStorageScheme
+	}
+}
+
 // extractAgeSecretKey extracts the AGE-SECRET-KEY from the input using
 // the age library's parser, which handles comments and whitespace.
 func extractAgeSecretKey(input string) string {
@@ -329,11 +397,14 @@ func extractAgeSecretKey(input string) string {
 	if id, ok := identities[0].(*age.X25519Identity); ok {
 		return id.String()
 	}
+
 	return strings.TrimSpace(input)
 }
 
 // Module exports the config module for fx dependency injection.
 // It provides the Config type to other modules in the application.
+//
+//nolint:gochecknoglobals // fx module definitions are package globals
 var Module = fx.Module("config",
 	fx.Provide(New),
 )

internal/config/config_test.go

@@ -1,4 +1,4 @@
-package config
+package config //nolint:testpackage // exercises unexported extractAgeSecretKey
 
 import (
 	"os"
@@ -7,15 +7,20 @@ import (
 )
 
 const (
-	TEST_SNEAK_AGE_PUBLIC_KEY        = "age1278m9q7dp3chsh2dcy82qk27v047zywyvtxwnj4cvt0z65jw6a7q5dqhfj"
-	TEST_INTEGRATION_AGE_PUBLIC_KEY  = "age1ezrjmfpwsc95svdg0y54mums3zevgzu0x0ecq2f7tp8a05gl0sjq9q9wjg"
-	TEST_INTEGRATION_AGE_PRIVATE_KEY = "AGE-SECRET-KEY-19CR5YSFW59HM4TLD6GXVEDMZFTVVF7PPHKUT68TXSFPK7APHXA2QS2NJA5"
+	testSneakAgePublicKey = "age1278m9q7dp3chsh2dcy82qk27v047zywyvt" +
+		"xwnj4cvt0z65jw6a7q5dqhfj"
+	testIntegrationAgePublicKey = "age1ezrjmfpwsc95svdg0y54mums3zevgzu" +
+		"0x0ecq2f7tp8a05gl0sjq9q9wjg"
+	testIntegrationAgePrivateKey = "AGE-SECRET-KEY-19CR5YSFW59HM4TLD6GX" +
+		"VEDMZFTVVF7PPHKUT68TXSFPK7APHXA2QS2NJA5"
 )
 
 func TestMain(m *testing.M) {
 	// Set up test environment
 	testConfigPath := filepath.Join("..", "..", "test", "config.yaml")
-	if absPath, err := filepath.Abs(testConfigPath); err == nil {
+
+	absPath, err := filepath.Abs(testConfigPath)
+	if err == nil {
 		_ = os.Setenv("VAULTIK_CONFIG", absPath)
 	}
 
@@ -23,8 +28,11 @@ func TestMain(m *testing.M) {
 	os.Exit(code)
 }
 
-// TestConfigLoad ensures the config package can be imported and basic functionality works
+// TestConfigLoad ensures the config package can be imported and basic
+// functionality works.
 func TestConfigLoad(t *testing.T) {
+	t.Parallel()
+
 	// Use the test config file
 	configPath := os.Getenv("VAULTIK_CONFIG")
 	if configPath == "" {
@@ -41,8 +49,10 @@ func TestConfigLoad(t *testing.T) {
 	if len(cfg.AgeRecipients) != 2 {
 		t.Errorf("Expected 2 age recipients, got %d", len(cfg.AgeRecipients))
 	}
-	if cfg.AgeRecipients[0] != TEST_SNEAK_AGE_PUBLIC_KEY {
-		t.Errorf("Expected first age recipient to be %s, got '%s'", TEST_SNEAK_AGE_PUBLIC_KEY, cfg.AgeRecipients[0])
+
+	if cfg.AgeRecipients[0] != testSneakAgePublicKey {
+		t.Errorf("Expected first age recipient to be %s, got '%s'",
+			testSneakAgePublicKey, cfg.AgeRecipients[0])
 	}
 
 	if len(cfg.Snapshots) != 1 {
@@ -59,11 +69,13 @@ func TestConfigLoad(t *testing.T) {
 	}
 
 	if testSnap.Paths[0] != "/tmp/vaultik-test-source" {
-		t.Errorf("Expected first path to be '/tmp/vaultik-test-source', got '%s'", testSnap.Paths[0])
+		t.Errorf("Expected first path to be '/tmp/vaultik-test-source', got '%s'",
+			testSnap.Paths[0])
 	}
 
 	if cfg.S3.Bucket != "vaultik-test-bucket" {
-		t.Errorf("Expected S3 bucket to be 'vaultik-test-bucket', got '%s'", cfg.S3.Bucket)
+		t.Errorf("Expected S3 bucket to be 'vaultik-test-bucket', got '%s'",
+			cfg.S3.Bucket)
 	}
 
 	if cfg.Hostname != "test-host" {
@@ -73,19 +85,26 @@ func TestConfigLoad(t *testing.T) {
 
 // TestConfigFromEnv tests loading config path from environment variable
 func TestConfigFromEnv(t *testing.T) {
+	t.Parallel()
+
 	configPath := os.Getenv("VAULTIK_CONFIG")
 	if configPath == "" {
 		t.Skip("VAULTIK_CONFIG not set")
 	}
 
 	// Verify the file exists
-	if _, err := os.Stat(configPath); os.IsNotExist(err) {
-		t.Errorf("Config file does not exist at path from VAULTIK_CONFIG: %s", configPath)
+	//nolint:gosec // G703: test config path comes from the test environment
+	_, err := os.Stat(configPath)
+	if os.IsNotExist(err) {
+		t.Errorf("Config file does not exist at path from VAULTIK_CONFIG: %s",
+			configPath)
 	}
 }
 
 // TestExtractAgeSecretKey tests extraction of AGE-SECRET-KEY from various inputs
 func TestExtractAgeSecretKey(t *testing.T) {
+	t.Parallel()
+
 	tests := []struct {
 		name     string
 		input    string
@@ -93,36 +112,32 @@ func TestExtractAgeSecretKey(t *testing.T) {
 	}{
 		{
 			name:     "plain key",
-			input:    "AGE-SECRET-KEY-19CR5YSFW59HM4TLD6GXVEDMZFTVVF7PPHKUT68TXSFPK7APHXA2QS2NJA5",
-			expected: "AGE-SECRET-KEY-19CR5YSFW59HM4TLD6GXVEDMZFTVVF7PPHKUT68TXSFPK7APHXA2QS2NJA5",
+			input:    testIntegrationAgePrivateKey,
+			expected: testIntegrationAgePrivateKey,
 		},
 		{
 			name:     "key with trailing newline",
-			input:    "AGE-SECRET-KEY-19CR5YSFW59HM4TLD6GXVEDMZFTVVF7PPHKUT68TXSFPK7APHXA2QS2NJA5\n",
-			expected: "AGE-SECRET-KEY-19CR5YSFW59HM4TLD6GXVEDMZFTVVF7PPHKUT68TXSFPK7APHXA2QS2NJA5",
+			input:    testIntegrationAgePrivateKey + "\n",
+			expected: testIntegrationAgePrivateKey,
 		},
 		{
 			name: "full age-keygen output",
-			input: `# created: 2025-01-14T12:00:00Z
-# public key: age1ezrjmfpwsc95svdg0y54mums3zevgzu0x0ecq2f7tp8a05gl0sjq9q9wjg
-AGE-SECRET-KEY-19CR5YSFW59HM4TLD6GXVEDMZFTVVF7PPHKUT68TXSFPK7APHXA2QS2NJA5
-`,
-			expected: "AGE-SECRET-KEY-19CR5YSFW59HM4TLD6GXVEDMZFTVVF7PPHKUT68TXSFPK7APHXA2QS2NJA5",
+			input: "# created: 2025-01-14T12:00:00Z\n" +
+				"# public key: " + testIntegrationAgePublicKey + "\n" +
+				testIntegrationAgePrivateKey + "\n",
+			expected: testIntegrationAgePrivateKey,
 		},
 		{
 			name: "age-keygen output with extra blank lines",
-			input: `# created: 2025-01-14T12:00:00Z
-# public key: age1ezrjmfpwsc95svdg0y54mums3zevgzu0x0ecq2f7tp8a05gl0sjq9q9wjg
-
-AGE-SECRET-KEY-19CR5YSFW59HM4TLD6GXVEDMZFTVVF7PPHKUT68TXSFPK7APHXA2QS2NJA5
-
-`,
-			expected: "AGE-SECRET-KEY-19CR5YSFW59HM4TLD6GXVEDMZFTVVF7PPHKUT68TXSFPK7APHXA2QS2NJA5",
+			input: "# created: 2025-01-14T12:00:00Z\n" +
+				"# public key: " + testIntegrationAgePublicKey + "\n\n" +
+				testIntegrationAgePrivateKey + "\n\n",
+			expected: testIntegrationAgePrivateKey,
 		},
 		{
 			name:     "key with leading whitespace",
-			input:    "  AGE-SECRET-KEY-19CR5YSFW59HM4TLD6GXVEDMZFTVVF7PPHKUT68TXSFPK7APHXA2QS2NJA5  ",
-			expected: "AGE-SECRET-KEY-19CR5YSFW59HM4TLD6GXVEDMZFTVVF7PPHKUT68TXSFPK7APHXA2QS2NJA5",
+			input:    "  " + testIntegrationAgePrivateKey + "  ",
+			expected: testIntegrationAgePrivateKey,
 		},
 		{
 			name:     "empty input",
@@ -138,9 +153,12 @@ AGE-SECRET-KEY-19CR5YSFW59HM4TLD6GXVEDMZFTVVF7PPHKUT68TXSFPK7APHXA2QS2NJA5
 
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
+
 			result := extractAgeSecretKey(tt.input)
 			if result != tt.expected {
-				t.Errorf("extractAgeSecretKey(%q) = %q, want %q", tt.input, result, tt.expected)
+				t.Errorf("extractAgeSecretKey(%q) = %q, want %q",
+					tt.input, result, tt.expected)
 			}
 		})
 	}

internal/config/size.go

@@ -1,31 +1,45 @@
 package config
 
 import (
+	"errors"
 	"fmt"
+	"math"
 
 	"github.com/dustin/go-humanize"
 )
 
+var (
+	errSizeType     = errors.New("size must be a number or string")
+	errSizeTooLarge = errors.New("size exceeds maximum supported value")
+)
+
 // Size represents a byte size that can be specified in configuration files.
 // It can unmarshal from both numeric values (interpreted as bytes) and
 // human-readable strings like "10MB", "2.5GB", or "1TB".
+//
+//nolint:recvcheck // UnmarshalYAML requires a pointer; String/Int64 are value reads
 type Size int64
 
 // UnmarshalYAML implements yaml.Unmarshaler for Size, allowing it to be
 // parsed from YAML configuration files. It accepts both numeric values
 // (interpreted as bytes) and string values with units (e.g., "10MB").
-func (s *Size) UnmarshalYAML(unmarshal func(interface{}) error) error {
+func (s *Size) UnmarshalYAML(unmarshal func(any) error) error {
 	// Try to unmarshal as int64 first
 	var intVal int64
-	if err := unmarshal(&intVal); err == nil {
+
+	err := unmarshal(&intVal)
+	if err == nil {
 		*s = Size(intVal)
+
 		return nil
 	}
 
 	// Try to unmarshal as string
 	var strVal string
-	if err := unmarshal(&strVal); err != nil {
-		return fmt.Errorf("size must be a number or string")
+
+	err = unmarshal(&strVal)
+	if err != nil {
+		return errSizeType
 	}
 
 	// Parse the string using go-humanize
@@ -34,7 +48,12 @@ func (s *Size) UnmarshalYAML(unmarshal func(interface{}) error) error {
 		return fmt.Errorf("invalid size format: %w", err)
 	}
 
+	if bytes > math.MaxInt64 {
+		return fmt.Errorf("%w: %s", errSizeTooLarge, strVal)
+	}
+
 	*s = Size(bytes)
+
 	return nil
 }
 
@@ -49,6 +68,7 @@ func (s Size) Int64() int64 {
 // For example, 1048576 bytes would be formatted as "1.0 MB".
 // This implements the fmt.Stringer interface.
 func (s Size) String() string {
+	//nolint:gosec // G115: sizes are non-negative by construction
 	return humanize.Bytes(uint64(s))
 }
 
@@ -58,5 +78,10 @@ func ParseSize(s string) (Size, error) {
 	if err != nil {
 		return 0, fmt.Errorf("invalid size format: %w", err)
 	}
+
+	if bytes > math.MaxInt64 {
+		return 0, fmt.Errorf("%w: %s", errSizeTooLarge, s)
+	}
+
 	return Size(bytes), nil
 }

internal/crypto/encryption.go

@@ -1,7 +1,10 @@
+// Package crypto provides thread-safe age encryption and decryption
+// helpers used to protect blob and metadata content.
 package crypto
 
 import (
 	"bytes"
+	"errors"
 	"fmt"
 	"io"
 	"sync"
@@ -10,6 +13,10 @@ import (
 	"go.uber.org/fx"
 )
 
+// ErrNoRecipients is returned when an encryptor is created or updated
+// without any recipient public keys.
+var ErrNoRecipients = errors.New("at least one recipient is required")
+
 // Encryptor provides thread-safe encryption using the age encryption library.
 // It supports encrypting data for multiple recipients simultaneously, allowing
 // any of the corresponding private keys to decrypt the data. This is useful
@@ -25,7 +32,7 @@ type Encryptor struct {
 // public keys are invalid or if no recipients are specified.
 func NewEncryptor(publicKeys []string) (*Encryptor, error) {
 	if len(publicKeys) == 0 {
-		return nil, fmt.Errorf("at least one recipient is required")
+		return nil, ErrNoRecipients
 	}
 
 	recipients := make([]age.Recipient, 0, len(publicKeys))
@@ -34,6 +41,7 @@ func NewEncryptor(publicKeys []string) (*Encryptor, error) {
 		if err != nil {
 			return nil, fmt.Errorf("parsing age recipient %s: %w", key, err)
 		}
+
 		recipients = append(recipients, recipient)
 	}
 
@@ -60,12 +68,14 @@ func (e *Encryptor) Encrypt(data []byte) ([]byte, error) {
 	}
 
 	// Write data
-	if _, err := w.Write(data); err != nil {
+	_, err = w.Write(data)
+	if err != nil {
 		return nil, fmt.Errorf("writing encrypted data: %w", err)
 	}
 
 	// Close to flush
-	if err := w.Close(); err != nil {
+	err = w.Close()
+	if err != nil {
 		return nil, fmt.Errorf("closing encrypted writer: %w", err)
 	}
 
@@ -88,12 +98,14 @@ func (e *Encryptor) EncryptStream(dst io.Writer, src io.Reader) error {
 	}
 
 	// Copy data
-	if _, err := io.Copy(w, src); err != nil {
+	_, err = io.Copy(w, src)
+	if err != nil {
 		return fmt.Errorf("copying encrypted data: %w", err)
 	}
 
 	// Close to flush
-	if err := w.Close(); err != nil {
+	err = w.Close()
+	if err != nil {
 		return fmt.Errorf("closing encrypted writer: %w", err)
 	}
 
@@ -126,7 +138,7 @@ func (e *Encryptor) EncryptWriter(dst io.Writer) (io.WriteCloser, error) {
 // of the public keys are invalid or if no recipients are specified.
 func (e *Encryptor) UpdateRecipients(publicKeys []string) error {
 	if len(publicKeys) == 0 {
-		return fmt.Errorf("at least one recipient is required")
+		return ErrNoRecipients
 	}
 
 	recipients := make([]age.Recipient, 0, len(publicKeys))
@@ -135,6 +147,7 @@ func (e *Encryptor) UpdateRecipients(publicKeys []string) error {
 		if err != nil {
 			return fmt.Errorf("parsing age recipient %s: %w", key, err)
 		}
+
 		recipients = append(recipients, recipient)
 	}
 
@@ -206,4 +219,6 @@ func (d *Decryptor) DecryptStream(src io.Reader) (io.Reader, error) {
 }
 
 // Module exports the crypto module for fx dependency injection.
+//
+//nolint:gochecknoglobals // fx module definitions are package globals
 var Module = fx.Module("crypto")

internal/crypto/encryption_test.go

@@ -1,13 +1,16 @@
-package crypto
+package crypto_test
 
 import (
 	"bytes"
 	"testing"
 
 	"filippo.io/age"
+	"sneak.berlin/go/vaultik/internal/crypto"
 )
 
 func TestEncryptor(t *testing.T) {
+	t.Parallel()
+
 	// Generate a test key pair
 	identity, err := age.GenerateX25519Identity()
 	if err != nil {
@@ -17,7 +20,7 @@ func TestEncryptor(t *testing.T) {
 	publicKey := identity.Recipient().String()
 
 	// Create encryptor
-	enc, err := NewEncryptor([]string{publicKey})
+	enc, err := crypto.NewEncryptor([]string{publicKey})
 	if err != nil {
 		t.Fatalf("failed to create encryptor: %v", err)
 	}
@@ -43,7 +46,9 @@ func TestEncryptor(t *testing.T) {
 	}
 
 	var decrypted bytes.Buffer
-	if _, err := decrypted.ReadFrom(r); err != nil {
+
+	_, err = decrypted.ReadFrom(r)
+	if err != nil {
 		t.Fatalf("failed to read decrypted data: %v", err)
 	}
 
@@ -53,15 +58,19 @@ func TestEncryptor(t *testing.T) {
 }
 
 func TestEncryptorMultipleRecipients(t *testing.T) {
+	t.Parallel()
+
 	// Generate three test key pairs
 	identity1, err := age.GenerateX25519Identity()
 	if err != nil {
 		t.Fatalf("failed to generate identity1: %v", err)
 	}
+
 	identity2, err := age.GenerateX25519Identity()
 	if err != nil {
 		t.Fatalf("failed to generate identity2: %v", err)
 	}
+
 	identity3, err := age.GenerateX25519Identity()
 	if err != nil {
 		t.Fatalf("failed to generate identity3: %v", err)
@@ -74,7 +83,7 @@ func TestEncryptorMultipleRecipients(t *testing.T) {
 	}
 
 	// Create encryptor with multiple recipients
-	enc, err := NewEncryptor(publicKeys)
+	enc, err := crypto.NewEncryptor(publicKeys)
 	if err != nil {
 		t.Fatalf("failed to create encryptor: %v", err)
 	}
@@ -97,7 +106,9 @@ func TestEncryptorMultipleRecipients(t *testing.T) {
 		}
 
 		var decrypted bytes.Buffer
-		if _, err := decrypted.ReadFrom(r); err != nil {
+
+		_, err = decrypted.ReadFrom(r)
+		if err != nil {
 			t.Fatalf("recipient %d failed to read decrypted data: %v", i+1, err)
 		}
 
@@ -108,6 +119,8 @@ func TestEncryptorMultipleRecipients(t *testing.T) {
 }
 
 func TestEncryptorUpdateRecipients(t *testing.T) {
+	t.Parallel()
+
 	// Generate two identities
 	identity1, _ := age.GenerateX25519Identity()
 	identity2, _ := age.GenerateX25519Identity()
@@ -116,20 +129,22 @@ func TestEncryptorUpdateRecipients(t *testing.T) {
 	publicKey2 := identity2.Recipient().String()
 
 	// Create encryptor with first key
-	enc, err := NewEncryptor([]string{publicKey1})
+	enc, err := crypto.NewEncryptor([]string{publicKey1})
 	if err != nil {
 		t.Fatalf("failed to create encryptor: %v", err)
 	}
 
 	// Encrypt with first key
 	plaintext := []byte("test data")
+
 	ciphertext1, err := enc.Encrypt(plaintext)
 	if err != nil {
 		t.Fatalf("failed to encrypt: %v", err)
 	}
 
 	// Update to second key
-	if err := enc.UpdateRecipients([]string{publicKey2}); err != nil {
+	err = enc.UpdateRecipients([]string{publicKey2})
+	if err != nil {
 		t.Fatalf("failed to update recipients: %v", err)
 	}
 
@@ -140,18 +155,24 @@ func TestEncryptorUpdateRecipients(t *testing.T) {
 	}
 
 	// First ciphertext should only decrypt with first identity
-	if _, err := age.Decrypt(bytes.NewReader(ciphertext1), identity1); err != nil {
+	_, err = age.Decrypt(bytes.NewReader(ciphertext1), identity1)
+	if err != nil {
 		t.Error("failed to decrypt with identity1")
 	}
-	if _, err := age.Decrypt(bytes.NewReader(ciphertext1), identity2); err == nil {
+
+	_, err = age.Decrypt(bytes.NewReader(ciphertext1), identity2)
+	if err == nil {
 		t.Error("should not decrypt with identity2")
 	}
 
 	// Second ciphertext should only decrypt with second identity
-	if _, err := age.Decrypt(bytes.NewReader(ciphertext2), identity2); err != nil {
+	_, err = age.Decrypt(bytes.NewReader(ciphertext2), identity2)
+	if err != nil {
 		t.Error("failed to decrypt with identity2")
 	}
-	if _, err := age.Decrypt(bytes.NewReader(ciphertext2), identity1); err == nil {
+
+	_, err = age.Decrypt(bytes.NewReader(ciphertext2), identity1)
+	if err == nil {
 		t.Error("should not decrypt with identity1")
 	}
 }

internal/database/blob_chunks.go

@@ -3,18 +3,25 @@ package database
 import (
 	"context"
 	"database/sql"
+	"errors"
 	"fmt"
 )
 
+// BlobChunkRepository provides access to the blob_chunks table, which maps
+// blobs to the chunks they contain (with offset and length).
 type BlobChunkRepository struct {
 	db *DB
 }
 
+// NewBlobChunkRepository creates a BlobChunkRepository backed by db.
 func NewBlobChunkRepository(db *DB) *BlobChunkRepository {
 	return &BlobChunkRepository{db: db}
 }
 
-func (r *BlobChunkRepository) Create(ctx context.Context, tx *sql.Tx, bc *BlobChunk) error {
+// Create inserts a blob_chunks row, using tx when non-nil.
+func (r *BlobChunkRepository) Create(
+	ctx context.Context, tx *sql.Tx, bc *BlobChunk,
+) error {
 	query := `
 		INSERT INTO blob_chunks (blob_id, chunk_hash, offset, length)
 		VALUES (?, ?, ?, ?)
@@ -34,7 +41,11 @@ func (r *BlobChunkRepository) Create(ctx context.Context, tx *sql.Tx, bc *BlobCh
 	return nil
 }
 
-func (r *BlobChunkRepository) GetByBlobID(ctx context.Context, blobID string) ([]*BlobChunk, error) {
+// GetByBlobID returns all chunks contained in the given blob, ordered by
+// their offset within the blob.
+func (r *BlobChunkRepository) GetByBlobID(
+	ctx context.Context, blobID string,
+) ([]*BlobChunk, error) {
 	query := `
 		SELECT blob_id, chunk_hash, offset, length
 		FROM blob_chunks
@@ -49,19 +60,26 @@ func (r *BlobChunkRepository) GetByBlobID(ctx context.Context, blobID string) ([
 	defer CloseRows(rows)
 
 	var blobChunks []*BlobChunk
+
 	for rows.Next() {
 		var bc BlobChunk
+
 		err := rows.Scan(&bc.BlobID, &bc.ChunkHash, &bc.Offset, &bc.Length)
 		if err != nil {
 			return nil, fmt.Errorf("scanning blob chunk: %w", err)
 		}
+
 		blobChunks = append(blobChunks, &bc)
 	}
 
 	return blobChunks, rows.Err()
 }
 
-func (r *BlobChunkRepository) GetByChunkHash(ctx context.Context, chunkHash string) (*BlobChunk, error) {
+// GetByChunkHash returns one blob_chunks row containing the given chunk,
+// or nil if the chunk is not packed in any blob.
+func (r *BlobChunkRepository) GetByChunkHash(
+	ctx context.Context, chunkHash string,
+) (*BlobChunk, error) {
 	query := `
 		SELECT blob_id, chunk_hash, offset, length
 		FROM blob_chunks
@@ -70,7 +88,9 @@ func (r *BlobChunkRepository) GetByChunkHash(ctx context.Context, chunkHash stri
 	`
 
 	LogSQL("GetByChunkHash", query, chunkHash)
+
 	var bc BlobChunk
+
 	err := r.db.conn.QueryRowContext(ctx, query, chunkHash).Scan(
 		&bc.BlobID,
 		&bc.ChunkHash,
@@ -78,21 +98,27 @@ func (r *BlobChunkRepository) GetByChunkHash(ctx context.Context, chunkHash stri
 		&bc.Length,
 	)
 
-	if err == sql.ErrNoRows {
+	if errors.Is(err, sql.ErrNoRows) {
 		LogSQL("GetByChunkHash", "No rows found", chunkHash)
-		return nil, nil
+
+		return nil, nil //nolint:nilnil // nil,nil signals not-found; callers check nil
 	}
+
 	if err != nil {
 		LogSQL("GetByChunkHash", "Error", chunkHash, err)
+
 		return nil, fmt.Errorf("querying blob chunk: %w", err)
 	}
 
 	LogSQL("GetByChunkHash", "Found blob", chunkHash, "blob", bc.BlobID)
+
 	return &bc, nil
 }
 
 // GetByChunkHashTx retrieves a blob chunk within a transaction
-func (r *BlobChunkRepository) GetByChunkHashTx(ctx context.Context, tx *sql.Tx, chunkHash string) (*BlobChunk, error) {
+func (r *BlobChunkRepository) GetByChunkHashTx(
+	ctx context.Context, tx *sql.Tx, chunkHash string,
+) (*BlobChunk, error) {
 	query := `
 		SELECT blob_id, chunk_hash, offset, length
 		FROM blob_chunks
@@ -101,7 +127,9 @@ func (r *BlobChunkRepository) GetByChunkHashTx(ctx context.Context, tx *sql.Tx,
 	`
 
 	LogSQL("GetByChunkHashTx", query, chunkHash)
+
 	var bc BlobChunk
+
 	err := tx.QueryRowContext(ctx, query, chunkHash).Scan(
 		&bc.BlobID,
 		&bc.ChunkHash,
@@ -109,20 +137,25 @@ func (r *BlobChunkRepository) GetByChunkHashTx(ctx context.Context, tx *sql.Tx,
 		&bc.Length,
 	)
 
-	if err == sql.ErrNoRows {
+	if errors.Is(err, sql.ErrNoRows) {
 		LogSQL("GetByChunkHashTx", "No rows found", chunkHash)
-		return nil, nil
+
+		return nil, nil //nolint:nilnil // nil,nil signals not-found; callers check nil
 	}
+
 	if err != nil {
 		LogSQL("GetByChunkHashTx", "Error", chunkHash, err)
+
 		return nil, fmt.Errorf("querying blob chunk: %w", err)
 	}
 
 	LogSQL("GetByChunkHashTx", "Found blob", chunkHash, "blob", bc.BlobID)
+
 	return &bc, nil
 }
 
-// DeleteOrphaned deletes blob_chunks entries where either the blob or chunk no longer exists
+// DeleteOrphaned deletes blob_chunks entries where either the blob or the
+// chunk no longer exists.
 func (r *BlobChunkRepository) DeleteOrphaned(ctx context.Context) error {
 	// Delete blob_chunks where the blob doesn't exist
 	query1 := `
@@ -132,7 +165,9 @@ func (r *BlobChunkRepository) DeleteOrphaned(ctx context.Context) error {
 			WHERE blobs.id = blob_chunks.blob_id
 		)
 	`
-	if _, err := r.db.ExecWithLog(ctx, query1); err != nil {
+
+	_, err := r.db.ExecWithLog(ctx, query1)
+	if err != nil {
 		return fmt.Errorf("deleting blob_chunks with missing blobs: %w", err)
 	}
 
@@ -144,7 +179,9 @@ func (r *BlobChunkRepository) DeleteOrphaned(ctx context.Context) error {
 			WHERE chunks.chunk_hash = blob_chunks.chunk_hash
 		)
 	`
-	if _, err := r.db.ExecWithLog(ctx, query2); err != nil {
+
+	_, err = r.db.ExecWithLog(ctx, query2)
+	if err != nil {
 		return fmt.Errorf("deleting blob_chunks with missing chunks: %w", err)
 	}
 

internal/database/blob_chunks_test.go

@@ -1,4 +1,4 @@
-package database
+package database_test
 
 import (
 	"context"
@@ -6,71 +6,107 @@ import (
 	"testing"
 	"time"
 
+	"sneak.berlin/go/vaultik/internal/database"
 	"sneak.berlin/go/vaultik/internal/types"
 )
 
-func TestBlobChunkRepository(t *testing.T) {
-	db, cleanup := setupTestDB(t)
-	defer cleanup()
+// Chunk hashes used across the blob_chunks tests.
+const (
+	chunk1Hash = "chunk1"
+	chunk2Hash = "chunk2"
+	chunk3Hash = "chunk3"
+)
+
+// mustCreateChunks registers the given chunk hashes (1024 bytes each).
+func mustCreateChunks(
+	t *testing.T,
+	repos *database.Repositories,
+	hashes ...types.ChunkHash,
+) {
+	t.Helper()
 
 	ctx := context.Background()
-	repos := NewRepositories(db)
 
-	// Create blob first
-	blob := &Blob{
-		ID:        types.NewBlobID(),
-		Hash:      types.BlobHash("blob1-hash"),
-		CreatedTS: time.Now(),
-	}
-	err := repos.Blobs.Create(ctx, nil, blob)
-	if err != nil {
-		t.Fatalf("failed to create blob: %v", err)
-	}
-
-	// Create chunks
-	chunks := []types.ChunkHash{"chunk1", "chunk2", "chunk3"}
-	for _, chunkHash := range chunks {
-		chunk := &Chunk{
+	for _, chunkHash := range hashes {
+		chunk := &database.Chunk{
 			ChunkHash: chunkHash,
 			Size:      1024,
 		}
-		err = repos.Chunks.Create(ctx, nil, chunk)
+
+		err := repos.Chunks.Create(ctx, nil, chunk)
 		if err != nil {
 			t.Fatalf("failed to create chunk %s: %v", chunkHash, err)
 		}
 	}
+}
+
+// mustCreateBlob creates a blob row with the given hash.
+func mustCreateBlob(
+	t *testing.T,
+	repos *database.Repositories,
+	hash types.BlobHash,
+) *database.Blob {
+	t.Helper()
+
+	blob := &database.Blob{
+		ID:        types.NewBlobID(),
+		Hash:      hash,
+		CreatedTS: time.Now(),
+	}
+
+	err := repos.Blobs.Create(context.Background(), nil, blob)
+	if err != nil {
+		t.Fatalf("failed to create blob %s: %v", hash, err)
+	}
+
+	return blob
+}
+
+func TestBlobChunkRepository(t *testing.T) {
+	t.Parallel()
+
+	db, cleanup := setupTestDB(t)
+	defer cleanup()
+
+	ctx := context.Background()
+	repos := database.NewRepositories(db)
+
+	blob := mustCreateBlob(t, repos, "blob1-hash")
+	mustCreateChunks(t, repos, chunk1Hash, chunk2Hash, chunk3Hash)
 
 	// Test Create
-	bc1 := &BlobChunk{
+	bc1 := &database.BlobChunk{
 		BlobID:    blob.ID,
-		ChunkHash: types.ChunkHash("chunk1"),
+		ChunkHash: types.ChunkHash(chunk1Hash),
 		Offset:    0,
 		Length:    1024,
 	}
 
-	err = repos.BlobChunks.Create(ctx, nil, bc1)
+	err := repos.BlobChunks.Create(ctx, nil, bc1)
 	if err != nil {
 		t.Fatalf("failed to create blob chunk: %v", err)
 	}
 
 	// Add more chunks to the same blob
-	bc2 := &BlobChunk{
+	bc2 := &database.BlobChunk{
 		BlobID:    blob.ID,
-		ChunkHash: types.ChunkHash("chunk2"),
+		ChunkHash: types.ChunkHash(chunk2Hash),
 		Offset:    1024,
 		Length:    2048,
 	}
+
 	err = repos.BlobChunks.Create(ctx, nil, bc2)
 	if err != nil {
 		t.Fatalf("failed to create second blob chunk: %v", err)
 	}
 
-	bc3 := &BlobChunk{
+	bc3 := &database.BlobChunk{
 		BlobID:    blob.ID,
-		ChunkHash: types.ChunkHash("chunk3"),
+		ChunkHash: types.ChunkHash(chunk3Hash),
 		Offset:    3072,
 		Length:    512,
 	}
+
 	err = repos.BlobChunks.Create(ctx, nil, bc3)
 	if err != nil {
 		t.Fatalf("failed to create third blob chunk: %v", err)
@@ -81,6 +117,7 @@ func TestBlobChunkRepository(t *testing.T) {
 	if err != nil {
 		t.Fatalf("failed to get blob chunks: %v", err)
 	}
+
 	if len(blobChunks) != 3 {
 		t.Errorf("expected 3 chunks, got %d", len(blobChunks))
 	}
@@ -89,92 +126,97 @@ func TestBlobChunkRepository(t *testing.T) {
 	expectedOffsets := []int64{0, 1024, 3072}
 	for i, bc := range blobChunks {
 		if bc.Offset != expectedOffsets[i] {
-			t.Errorf("wrong chunk order: expected offset %d, got %d", expectedOffsets[i], bc.Offset)
+			t.Errorf("wrong chunk order: expected offset %d, got %d",
+				expectedOffsets[i], bc.Offset)
 		}
 	}
 
-	// Test GetByChunkHash
-	bc, err := repos.BlobChunks.GetByChunkHash(ctx, "chunk2")
-	if err != nil {
-		t.Fatalf("failed to get blob chunk by chunk hash: %v", err)
-	}
-	if bc == nil {
-		t.Fatal("expected blob chunk, got nil")
-	}
-	if bc.BlobID != blob.ID {
-		t.Errorf("wrong blob ID: expected %s, got %s", blob.ID, bc.BlobID)
-	}
-	if bc.Offset != 1024 {
-		t.Errorf("wrong offset: expected 1024, got %d", bc.Offset)
-	}
-
 	// Test duplicate insert (should fail due to primary key constraint)
 	err = repos.BlobChunks.Create(ctx, nil, bc1)
 	if err == nil {
 		t.Fatal("duplicate blob_chunk insert should fail due to primary key constraint")
 	}
-	if !strings.Contains(err.Error(), "UNIQUE") && !strings.Contains(err.Error(), "constraint") {
+
+	if !strings.Contains(err.Error(), "UNIQUE") &&
+		!strings.Contains(err.Error(), "constraint") {
 		t.Fatalf("expected constraint error, got: %v", err)
 	}
+}
+
+func TestBlobChunkRepositoryGetByChunkHash(t *testing.T) {
+	t.Parallel()
+
+	db, cleanup := setupTestDB(t)
+	defer cleanup()
+
+	ctx := context.Background()
+	repos := database.NewRepositories(db)
+
+	blob := mustCreateBlob(t, repos, "blob-gbch-hash")
+	mustCreateChunks(t, repos, chunk2Hash)
+
+	bc2 := &database.BlobChunk{
+		BlobID:    blob.ID,
+		ChunkHash: types.ChunkHash(chunk2Hash),
+		Offset:    1024,
+		Length:    2048,
+	}
+
+	err := repos.BlobChunks.Create(ctx, nil, bc2)
+	if err != nil {
+		t.Fatalf("failed to create blob chunk: %v", err)
+	}
+
+	// Test GetByChunkHash
+	bc, err := repos.BlobChunks.GetByChunkHash(ctx, chunk2Hash)
+	if err != nil {
+		t.Fatalf("failed to get blob chunk by chunk hash: %v", err)
+	}
+
+	if bc == nil {
+		t.Fatal("expected blob chunk, got nil")
+	}
+
+	if bc.BlobID != blob.ID {
+		t.Errorf("wrong blob ID: expected %s, got %s", blob.ID, bc.BlobID)
+	}
+
+	if bc.Offset != 1024 {
+		t.Errorf("wrong offset: expected 1024, got %d", bc.Offset)
+	}
 
 	// Test non-existent chunk
 	bc, err = repos.BlobChunks.GetByChunkHash(ctx, "nonexistent")
 	if err != nil {
 		t.Fatalf("unexpected error: %v", err)
 	}
+
 	if bc != nil {
 		t.Error("expected nil for non-existent chunk")
 	}
 }
 
 func TestBlobChunkRepositoryMultipleBlobs(t *testing.T) {
+	t.Parallel()
+
 	db, cleanup := setupTestDB(t)
 	defer cleanup()
 
 	ctx := context.Background()
-	repos := NewRepositories(db)
+	repos := database.NewRepositories(db)
 
-	// Create blobs
-	blob1 := &Blob{
-		ID:        types.NewBlobID(),
-		Hash:      types.BlobHash("blob1-hash"),
-		CreatedTS: time.Now(),
-	}
-	blob2 := &Blob{
-		ID:        types.NewBlobID(),
-		Hash:      types.BlobHash("blob2-hash"),
-		CreatedTS: time.Now(),
-	}
-
-	err := repos.Blobs.Create(ctx, nil, blob1)
-	if err != nil {
-		t.Fatalf("failed to create blob1: %v", err)
-	}
-	err = repos.Blobs.Create(ctx, nil, blob2)
-	if err != nil {
-		t.Fatalf("failed to create blob2: %v", err)
-	}
-
-	// Create chunks
-	chunkHashes := []types.ChunkHash{"chunk1", "chunk2", "chunk3"}
-	for _, chunkHash := range chunkHashes {
-		chunk := &Chunk{
-			ChunkHash: chunkHash,
-			Size:      1024,
-		}
-		err = repos.Chunks.Create(ctx, nil, chunk)
-		if err != nil {
-			t.Fatalf("failed to create chunk %s: %v", chunkHash, err)
-		}
-	}
+	blob1 := mustCreateBlob(t, repos, "blob1-hash")
+	blob2 := mustCreateBlob(t, repos, "blob2-hash")
+	mustCreateChunks(t, repos, chunk1Hash, chunk2Hash, chunk3Hash)
 
 	// Create chunks across multiple blobs
 	// Some chunks are shared between blobs (deduplication scenario)
-	blobChunks := []BlobChunk{
-		{BlobID: blob1.ID, ChunkHash: types.ChunkHash("chunk1"), Offset: 0, Length: 1024},
-		{BlobID: blob1.ID, ChunkHash: types.ChunkHash("chunk2"), Offset: 1024, Length: 1024},
-		{BlobID: blob2.ID, ChunkHash: types.ChunkHash("chunk2"), Offset: 0, Length: 1024}, // chunk2 is shared
-		{BlobID: blob2.ID, ChunkHash: types.ChunkHash("chunk3"), Offset: 1024, Length: 1024},
+	blobChunks := []database.BlobChunk{
+		{BlobID: blob1.ID, ChunkHash: chunk1Hash, Offset: 0, Length: 1024},
+		{BlobID: blob1.ID, ChunkHash: chunk2Hash, Offset: 1024, Length: 1024},
+		// chunk2 is shared between the blobs
+		{BlobID: blob2.ID, ChunkHash: chunk2Hash, Offset: 0, Length: 1024},
+		{BlobID: blob2.ID, ChunkHash: chunk3Hash, Offset: 1024, Length: 1024},
 	}
 
 	for _, bc := range blobChunks {
@@ -189,6 +231,7 @@ func TestBlobChunkRepositoryMultipleBlobs(t *testing.T) {
 	if err != nil {
 		t.Fatalf("failed to get blob1 chunks: %v", err)
 	}
+
 	if len(chunks) != 2 {
 		t.Errorf("expected 2 chunks for blob1, got %d", len(chunks))
 	}
@@ -198,15 +241,17 @@ func TestBlobChunkRepositoryMultipleBlobs(t *testing.T) {
 	if err != nil {
 		t.Fatalf("failed to get blob2 chunks: %v", err)
 	}
+
 	if len(chunks) != 2 {
 		t.Errorf("expected 2 chunks for blob2, got %d", len(chunks))
 	}
 
 	// Verify shared chunk
-	bc, err := repos.BlobChunks.GetByChunkHash(ctx, "chunk2")
+	bc, err := repos.BlobChunks.GetByChunkHash(ctx, chunk2Hash)
 	if err != nil {
 		t.Fatalf("failed to get shared chunk: %v", err)
 	}
+
 	if bc == nil {
 		t.Fatal("expected shared chunk, got nil")
 	}

internal/database/blobs.go

@@ -3,31 +3,39 @@ package database
 import (
 	"context"
 	"database/sql"
+	"errors"
 	"fmt"
 	"time"
 
 	"sneak.berlin/go/vaultik/internal/log"
 )
 
+// BlobRepository provides access to the blobs table, which tracks the
+// packed, encrypted storage units uploaded to the destination.
 type BlobRepository struct {
 	db *DB
 }
 
+// NewBlobRepository creates a BlobRepository backed by db.
 func NewBlobRepository(db *DB) *BlobRepository {
 	return &BlobRepository{db: db}
 }
 
+// Create inserts a blob row, using tx when non-nil.
 func (r *BlobRepository) Create(ctx context.Context, tx *sql.Tx, blob *Blob) error {
 	query := `
-		INSERT INTO blobs (id, blob_hash, created_ts, finished_ts, uncompressed_size, compressed_size, uploaded_ts)
+		INSERT INTO blobs (id, blob_hash, created_ts, finished_ts,
+			uncompressed_size, compressed_size, uploaded_ts)
 		VALUES (?, ?, ?, ?, ?, ?, ?)
 	`
 
 	var finishedTS, uploadedTS *int64
+
 	if blob.FinishedTS != nil {
 		ts := blob.FinishedTS.Unix()
 		finishedTS = &ts
 	}
+
 	if blob.UploadedTS != nil {
 		ts := blob.UploadedTS.Unix()
 		uploadedTS = &ts
@@ -49,85 +57,15 @@ func (r *BlobRepository) Create(ctx context.Context, tx *sql.Tx, blob *Blob) err
 	return nil
 }
 
+// GetByHash returns the blob with the given content hash, or nil if no
+// such blob exists.
 func (r *BlobRepository) GetByHash(ctx context.Context, hash string) (*Blob, error) {
-	query := `
-		SELECT id, blob_hash, created_ts, finished_ts, uncompressed_size, compressed_size, uploaded_ts
-		FROM blobs
-		WHERE blob_hash = ?
-	`
-
-	var blob Blob
-	var createdTSUnix int64
-	var finishedTSUnix, uploadedTSUnix sql.NullInt64
-
-	err := r.db.conn.QueryRowContext(ctx, query, hash).Scan(
-		&blob.ID,
-		&blob.Hash,
-		&createdTSUnix,
-		&finishedTSUnix,
-		&blob.UncompressedSize,
-		&blob.CompressedSize,
-		&uploadedTSUnix,
-	)
-
-	if err == sql.ErrNoRows {
-		return nil, nil
-	}
-	if err != nil {
-		return nil, fmt.Errorf("querying blob: %w", err)
-	}
-
-	blob.CreatedTS = time.Unix(createdTSUnix, 0).UTC()
-	if finishedTSUnix.Valid {
-		ts := time.Unix(finishedTSUnix.Int64, 0).UTC()
-		blob.FinishedTS = &ts
-	}
-	if uploadedTSUnix.Valid {
-		ts := time.Unix(uploadedTSUnix.Int64, 0).UTC()
-		blob.UploadedTS = &ts
-	}
-	return &blob, nil
+	return r.getOne(ctx, "blob_hash", hash)
 }
 
 // GetByID retrieves a blob by its ID
 func (r *BlobRepository) GetByID(ctx context.Context, id string) (*Blob, error) {
-	query := `
-		SELECT id, blob_hash, created_ts, finished_ts, uncompressed_size, compressed_size, uploaded_ts
-		FROM blobs
-		WHERE id = ?
-	`
-
-	var blob Blob
-	var createdTSUnix int64
-	var finishedTSUnix, uploadedTSUnix sql.NullInt64
-
-	err := r.db.conn.QueryRowContext(ctx, query, id).Scan(
-		&blob.ID,
-		&blob.Hash,
-		&createdTSUnix,
-		&finishedTSUnix,
-		&blob.UncompressedSize,
-		&blob.CompressedSize,
-		&uploadedTSUnix,
-	)
-
-	if err == sql.ErrNoRows {
-		return nil, nil
-	}
-	if err != nil {
-		return nil, fmt.Errorf("querying blob: %w", err)
-	}
-
-	blob.CreatedTS = time.Unix(createdTSUnix, 0).UTC()
-	if finishedTSUnix.Valid {
-		ts := time.Unix(finishedTSUnix.Int64, 0).UTC()
-		blob.FinishedTS = &ts
-	}
-	if uploadedTSUnix.Valid {
-		ts := time.Unix(uploadedTSUnix.Int64, 0).UTC()
-		blob.UploadedTS = &ts
-	}
-	return &blob, nil
+	return r.getOne(ctx, "id", id)
 }
 
 // GetAll returns every blob row keyed by blob ID. Useful at restore
@@ -135,7 +73,8 @@ func (r *BlobRepository) GetByID(ctx context.Context, id string) (*Blob, error)
 // into blob hashes without doing one GetByID query per chunk.
 func (r *BlobRepository) GetAll(ctx context.Context) (map[string]*Blob, error) {
 	query := `
-		SELECT id, blob_hash, created_ts, finished_ts, uncompressed_size, compressed_size, uploaded_ts
+		SELECT id, blob_hash, created_ts, finished_ts,
+			uncompressed_size, compressed_size, uploaded_ts
 		FROM blobs
 	`
 
@@ -146,11 +85,15 @@ func (r *BlobRepository) GetAll(ctx context.Context) (map[string]*Blob, error) {
 	defer CloseRows(rows)
 
 	out := make(map[string]*Blob)
+
 	for rows.Next() {
-		var blob Blob
-		var createdTSUnix int64
-		var finishedTSUnix, uploadedTSUnix sql.NullInt64
-		if err := rows.Scan(
+		var (
+			blob                           Blob
+			createdTSUnix                  int64
+			finishedTSUnix, uploadedTSUnix sql.NullInt64
+		)
+
+		err := rows.Scan(
 			&blob.ID,
 			&blob.Hash,
 			&createdTSUnix,
@@ -158,25 +101,36 @@ func (r *BlobRepository) GetAll(ctx context.Context) (map[string]*Blob, error) {
 			&blob.UncompressedSize,
 			&blob.CompressedSize,
 			&uploadedTSUnix,
-		); err != nil {
+		)
+		if err != nil {
 			return nil, fmt.Errorf("scanning blob: %w", err)
 		}
+
 		blob.CreatedTS = time.Unix(createdTSUnix, 0).UTC()
 		if finishedTSUnix.Valid {
 			ts := time.Unix(finishedTSUnix.Int64, 0).UTC()
 			blob.FinishedTS = &ts
 		}
+
 		if uploadedTSUnix.Valid {
 			ts := time.Unix(uploadedTSUnix.Int64, 0).UTC()
 			blob.UploadedTS = &ts
 		}
+
 		out[blob.ID.String()] = &blob
 	}
+
 	return out, rows.Err()
 }
 
 // UpdateFinished updates a blob when it's finalized
-func (r *BlobRepository) UpdateFinished(ctx context.Context, tx *sql.Tx, id string, hash string, uncompressedSize, compressedSize int64) error {
+func (r *BlobRepository) UpdateFinished(
+	ctx context.Context,
+	tx *sql.Tx,
+	id string,
+	hash string,
+	uncompressedSize, compressedSize int64,
+) error {
 	query := `
 		UPDATE blobs 
 		SET blob_hash = ?, finished_ts = ?, uncompressed_size = ?, compressed_size = ?
@@ -184,6 +138,7 @@ func (r *BlobRepository) UpdateFinished(ctx context.Context, tx *sql.Tx, id stri
 	`
 
 	now := time.Now().UTC().Unix()
+
 	var err error
 	if tx != nil {
 		_, err = tx.ExecContext(ctx, query, hash, now, uncompressedSize, compressedSize, id)
@@ -199,7 +154,9 @@ func (r *BlobRepository) UpdateFinished(ctx context.Context, tx *sql.Tx, id stri
 }
 
 // UpdateUploaded marks a blob as uploaded
-func (r *BlobRepository) UpdateUploaded(ctx context.Context, tx *sql.Tx, id string) error {
+func (r *BlobRepository) UpdateUploaded(
+	ctx context.Context, tx *sql.Tx, id string,
+) error {
 	query := `
 		UPDATE blobs 
 		SET uploaded_ts = ?
@@ -207,6 +164,7 @@ func (r *BlobRepository) UpdateUploaded(ctx context.Context, tx *sql.Tx, id stri
 	`
 
 	now := time.Now().UTC().Unix()
+
 	var err error
 	if tx != nil {
 		_, err = tx.ExecContext(ctx, query, now, id)
@@ -243,3 +201,52 @@ func (r *BlobRepository) DeleteOrphaned(ctx context.Context) error {
 
 	return nil
 }
+
+// getOne fetches a single blob row matched on the given column, or
+// (nil, nil) when no row matches.
+func (r *BlobRepository) getOne(
+	ctx context.Context, column, value string,
+) (*Blob, error) {
+	query := `
+		SELECT id, blob_hash, created_ts, finished_ts,
+			uncompressed_size, compressed_size, uploaded_ts
+		FROM blobs
+		WHERE ` + column + ` = ?`
+
+	var (
+		blob                           Blob
+		createdTSUnix                  int64
+		finishedTSUnix, uploadedTSUnix sql.NullInt64
+	)
+
+	err := r.db.conn.QueryRowContext(ctx, query, value).Scan(
+		&blob.ID,
+		&blob.Hash,
+		&createdTSUnix,
+		&finishedTSUnix,
+		&blob.UncompressedSize,
+		&blob.CompressedSize,
+		&uploadedTSUnix,
+	)
+
+	if errors.Is(err, sql.ErrNoRows) {
+		return nil, nil //nolint:nilnil // nil,nil signals not-found; callers check nil
+	}
+
+	if err != nil {
+		return nil, fmt.Errorf("querying blob: %w", err)
+	}
+
+	blob.CreatedTS = time.Unix(createdTSUnix, 0).UTC()
+	if finishedTSUnix.Valid {
+		ts := time.Unix(finishedTSUnix.Int64, 0).UTC()
+		blob.FinishedTS = &ts
+	}
+
+	if uploadedTSUnix.Valid {
+		ts := time.Unix(uploadedTSUnix.Int64, 0).UTC()
+		blob.UploadedTS = &ts
+	}
+
+	return &blob, nil
+}

internal/database/blobs_test.go

@@ -1,22 +1,25 @@
-package database
+package database_test
 
 import (
 	"context"
 	"testing"
 	"time"
 
+	"sneak.berlin/go/vaultik/internal/database"
 	"sneak.berlin/go/vaultik/internal/types"
 )
 
 func TestBlobRepository(t *testing.T) {
+	t.Parallel()
+
 	db, cleanup := setupTestDB(t)
 	defer cleanup()
 
 	ctx := context.Background()
-	repo := NewBlobRepository(db)
+	repo := database.NewBlobRepository(db)
 
 	// Test Create
-	blob := &Blob{
+	blob := &database.Blob{
 		ID:        types.NewBlobID(),
 		Hash:      types.BlobHash("blobhash123"),
 		CreatedTS: time.Now().Truncate(time.Second),
@@ -32,14 +35,18 @@ func TestBlobRepository(t *testing.T) {
 	if err != nil {
 		t.Fatalf("failed to get blob: %v", err)
 	}
+
 	if retrieved == nil {
 		t.Fatal("expected blob, got nil")
 	}
+
 	if retrieved.Hash != blob.Hash {
 		t.Errorf("blob hash mismatch: got %s, want %s", retrieved.Hash, blob.Hash)
 	}
+
 	if !retrieved.CreatedTS.Equal(blob.CreatedTS) {
-		t.Errorf("created timestamp mismatch: got %v, want %v", retrieved.CreatedTS, blob.CreatedTS)
+		t.Errorf("created timestamp mismatch: got %v, want %v",
+			retrieved.CreatedTS, blob.CreatedTS)
 	}
 
 	// Test GetByID
@@ -47,26 +54,51 @@ func TestBlobRepository(t *testing.T) {
 	if err != nil {
 		t.Fatalf("failed to get blob by ID: %v", err)
 	}
+
 	if retrievedByID == nil {
 		t.Fatal("expected blob, got nil")
 	}
+
 	if retrievedByID.ID != blob.ID {
 		t.Errorf("blob ID mismatch: got %s, want %s", retrievedByID.ID, blob.ID)
 	}
 
 	// Test with second blob
-	blob2 := &Blob{
+	blob2 := &database.Blob{
 		ID:        types.NewBlobID(),
 		Hash:      types.BlobHash("blobhash456"),
 		CreatedTS: time.Now().Truncate(time.Second),
 	}
+
 	err = repo.Create(ctx, nil, blob2)
 	if err != nil {
 		t.Fatalf("failed to create second blob: %v", err)
 	}
+}
+
+func TestBlobRepositoryUpdates(t *testing.T) {
+	t.Parallel()
+
+	db, cleanup := setupTestDB(t)
+	defer cleanup()
+
+	ctx := context.Background()
+	repo := database.NewBlobRepository(db)
+
+	blob := &database.Blob{
+		ID:        types.NewBlobID(),
+		Hash:      types.BlobHash("blobhash123"),
+		CreatedTS: time.Now().Truncate(time.Second),
+	}
+
+	err := repo.Create(ctx, nil, blob)
+	if err != nil {
+		t.Fatalf("failed to create blob: %v", err)
+	}
 
 	// Test UpdateFinished
 	now := time.Now()
+
 	err = repo.UpdateFinished(ctx, nil, blob.ID.String(), blob.Hash.String(), 1000, 500)
 	if err != nil {
 		t.Fatalf("failed to update blob as finished: %v", err)
@@ -77,12 +109,15 @@ func TestBlobRepository(t *testing.T) {
 	if err != nil {
 		t.Fatalf("failed to get updated blob: %v", err)
 	}
+
 	if updated.FinishedTS == nil {
 		t.Fatal("expected finished timestamp to be set")
 	}
+
 	if updated.UncompressedSize != 1000 {
 		t.Errorf("expected uncompressed size 1000, got %d", updated.UncompressedSize)
 	}
+
 	if updated.CompressedSize != 500 {
 		t.Errorf("expected compressed size 500, got %d", updated.CompressedSize)
 	}
@@ -98,6 +133,7 @@ func TestBlobRepository(t *testing.T) {
 	if err != nil {
 		t.Fatalf("failed to get uploaded blob: %v", err)
 	}
+
 	if uploaded.UploadedTS == nil {
 		t.Fatal("expected uploaded timestamp to be set")
 	}
@@ -108,13 +144,15 @@ func TestBlobRepository(t *testing.T) {
 }
 
 func TestBlobRepositoryDuplicate(t *testing.T) {
+	t.Parallel()
+
 	db, cleanup := setupTestDB(t)
 	defer cleanup()
 
 	ctx := context.Background()
-	repo := NewBlobRepository(db)
+	repo := database.NewBlobRepository(db)
 
-	blob := &Blob{
+	blob := &database.Blob{
 		ID:        types.NewBlobID(),
 		Hash:      types.BlobHash("duplicate_blob"),
 		CreatedTS: time.Now().Truncate(time.Second),

internal/database/cascade_debug_test.go

@@ -1,3 +1,4 @@
+//nolint:testpackage // inspects the unexported database connection
 package database
 
 import (
@@ -9,23 +10,13 @@ import (
 	"sneak.berlin/go/vaultik/internal/types"
 )
 
-// TestCascadeDeleteDebug tests cascade delete with debug output
-func TestCascadeDeleteDebug(t *testing.T) {
-	db, cleanup := setupTestDB(t)
-	defer cleanup()
+// createCascadeFixtures creates a file with three chunk mappings for the
+// cascade-delete test.
+func createCascadeFixtures(t *testing.T, repos *Repositories) *File {
+	t.Helper()
 
 	ctx := context.Background()
-	repos := NewRepositories(db)
 
-	// Check if foreign keys are enabled
-	var fkEnabled int
-	err := db.conn.QueryRow("PRAGMA foreign_keys").Scan(&fkEnabled)
-	if err != nil {
-		t.Fatal(err)
-	}
-	t.Logf("Foreign keys enabled: %d", fkEnabled)
-
-	// Create a file
 	file := &File{
 		Path:  "/cascade-test.txt",
 		MTime: time.Now().Truncate(time.Second),
@@ -34,18 +25,21 @@ func TestCascadeDeleteDebug(t *testing.T) {
 		UID:   1000,
 		GID:   1000,
 	}
-	err = repos.Files.Create(ctx, nil, file)
+
+	err := repos.Files.Create(ctx, nil, file)
 	if err != nil {
 		t.Fatalf("failed to create file: %v", err)
 	}
+
 	t.Logf("Created file with ID: %s", file.ID)
 
 	// Create chunks and file-chunk mappings
-	for i := 0; i < 3; i++ {
+	for i := range 3 {
 		chunk := &Chunk{
 			ChunkHash: types.ChunkHash(fmt.Sprintf("cascade-chunk-%d", i)),
 			Size:      1024,
 		}
+
 		err = repos.Chunks.Create(ctx, nil, chunk)
 		if err != nil {
 			t.Fatalf("failed to create chunk: %v", err)
@@ -56,33 +50,73 @@ func TestCascadeDeleteDebug(t *testing.T) {
 			Idx:       i,
 			ChunkHash: chunk.ChunkHash,
 		}
+
 		err = repos.FileChunks.Create(ctx, nil, fc)
 		if err != nil {
 			t.Fatalf("failed to create file chunk: %v", err)
 		}
-		t.Logf("Created file chunk mapping: file_id=%s, idx=%d, chunk=%s", fc.FileID, fc.Idx, fc.ChunkHash)
+
+		t.Logf("Created file chunk mapping: file_id=%s, idx=%d, chunk=%s",
+			fc.FileID, fc.Idx, fc.ChunkHash)
 	}
 
-	// Verify file chunks exist
-	fileChunks, err := repos.FileChunks.GetByFileID(ctx, file.ID)
+	return file
+}
+
+// logCascadeDebugInfo logs foreign-key state and the file_chunks table
+// definition for cascade-delete debugging.
+func logCascadeDebugInfo(ctx context.Context, t *testing.T, db *DB) {
+	t.Helper()
+
+	// Check if foreign keys are enabled
+	var fkEnabled int
+
+	err := db.conn.QueryRowContext(ctx, "PRAGMA foreign_keys").Scan(&fkEnabled)
 	if err != nil {
 		t.Fatal(err)
 	}
-	t.Logf("File chunks before delete: %d", len(fileChunks))
+
+	t.Logf("Foreign keys enabled: %d", fkEnabled)
 
 	// Check the foreign key constraint
 	var fkInfo string
-	err = db.conn.QueryRow(`
+
+	err = db.conn.QueryRowContext(ctx, `
 		SELECT sql FROM sqlite_master
 		WHERE type='table' AND name='file_chunks'
 	`).Scan(&fkInfo)
 	if err != nil {
 		t.Fatal(err)
 	}
+
 	t.Logf("file_chunks table definition:\n%s", fkInfo)
+}
+
+// TestCascadeDeleteDebug tests cascade delete with debug output
+func TestCascadeDeleteDebug(t *testing.T) {
+	t.Parallel()
+
+	db, cleanup := setupTestDB(t)
+	defer cleanup()
+
+	ctx := context.Background()
+	repos := NewRepositories(db)
+
+	logCascadeDebugInfo(ctx, t, db)
+
+	file := createCascadeFixtures(t, repos)
+
+	// Verify file chunks exist
+	fileChunks, err := repos.FileChunks.GetByFileID(ctx, file.ID)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	t.Logf("File chunks before delete: %d", len(fileChunks))
 
 	// Delete the file
 	t.Log("Deleting file...")
+
 	err = repos.Files.DeleteByID(ctx, nil, file.ID)
 	if err != nil {
 		t.Fatalf("failed to delete file: %v", err)
@@ -93,6 +127,7 @@ func TestCascadeDeleteDebug(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
+
 	if deletedFile != nil {
 		t.Error("file should have been deleted")
 	} else {
@@ -104,21 +139,27 @@ func TestCascadeDeleteDebug(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
+
 	t.Logf("File chunks after delete: %d", len(fileChunks))
 
 	// Manually check the database
 	var count int
-	err = db.conn.QueryRow("SELECT COUNT(*) FROM file_chunks WHERE file_id = ?", file.ID).Scan(&count)
+
+	err = db.conn.QueryRowContext(ctx,
+		"SELECT COUNT(*) FROM file_chunks WHERE file_id = ?", file.ID,
+	).Scan(&count)
 	if err != nil {
 		t.Fatal(err)
 	}
+
 	t.Logf("Manual count of file_chunks for deleted file: %d", count)
 
 	if len(fileChunks) != 0 {
 		t.Errorf("expected 0 file chunks after cascade delete, got %d", len(fileChunks))
 		// List the remaining chunks
 		for _, fc := range fileChunks {
-			t.Logf("Remaining chunk: file_id=%s, idx=%d, chunk=%s", fc.FileID, fc.Idx, fc.ChunkHash)
+			t.Logf("Remaining chunk: file_id=%s, idx=%d, chunk=%s",
+				fc.FileID, fc.Idx, fc.ChunkHash)
 		}
 	}
 }

internal/database/chunk_files.go

@@ -4,19 +4,26 @@ import (
 	"context"
 	"database/sql"
 	"fmt"
+	"strings"
 
 	"sneak.berlin/go/vaultik/internal/types"
 )
 
+// ChunkFileRepository provides access to the chunk_files table, the
+// reverse mapping from chunks to the files that contain them.
 type ChunkFileRepository struct {
 	db *DB
 }
 
+// NewChunkFileRepository creates a ChunkFileRepository backed by db.
 func NewChunkFileRepository(db *DB) *ChunkFileRepository {
 	return &ChunkFileRepository{db: db}
 }
 
-func (r *ChunkFileRepository) Create(ctx context.Context, tx *sql.Tx, cf *ChunkFile) error {
+// Create inserts a chunk_files row (idempotently), using tx when non-nil.
+func (r *ChunkFileRepository) Create(
+	ctx context.Context, tx *sql.Tx, cf *ChunkFile,
+) error {
 	query := `
 		INSERT INTO chunk_files (chunk_hash, file_id, file_offset, length)
 		VALUES (?, ?, ?, ?)
@@ -25,9 +32,11 @@ func (r *ChunkFileRepository) Create(ctx context.Context, tx *sql.Tx, cf *ChunkF
 
 	var err error
 	if tx != nil {
-		_, err = tx.ExecContext(ctx, query, cf.ChunkHash.String(), cf.FileID.String(), cf.FileOffset, cf.Length)
+		_, err = tx.ExecContext(ctx, query,
+			cf.ChunkHash.String(), cf.FileID.String(), cf.FileOffset, cf.Length)
 	} else {
-		_, err = r.db.ExecWithLog(ctx, query, cf.ChunkHash.String(), cf.FileID.String(), cf.FileOffset, cf.Length)
+		_, err = r.db.ExecWithLog(ctx, query,
+			cf.ChunkHash.String(), cf.FileID.String(), cf.FileOffset, cf.Length)
 	}
 
 	if err != nil {
@@ -37,7 +46,10 @@ func (r *ChunkFileRepository) Create(ctx context.Context, tx *sql.Tx, cf *ChunkF
 	return nil
 }
 
-func (r *ChunkFileRepository) GetByChunkHash(ctx context.Context, chunkHash types.ChunkHash) ([]*ChunkFile, error) {
+// GetByChunkHash returns all chunk_files rows for the given chunk hash.
+func (r *ChunkFileRepository) GetByChunkHash(
+	ctx context.Context, chunkHash types.ChunkHash,
+) ([]*ChunkFile, error) {
 	query := `
 		SELECT chunk_hash, file_id, file_offset, length
 		FROM chunk_files
@@ -53,7 +65,10 @@ func (r *ChunkFileRepository) GetByChunkHash(ctx context.Context, chunkHash type
 	return r.scanChunkFiles(rows)
 }
 
-func (r *ChunkFileRepository) GetByFilePath(ctx context.Context, filePath string) ([]*ChunkFile, error) {
+// GetByFilePath returns all chunk_files rows for the file at the given path.
+func (r *ChunkFileRepository) GetByFilePath(
+	ctx context.Context, filePath string,
+) ([]*ChunkFile, error) {
 	query := `
 		SELECT cf.chunk_hash, cf.file_id, cf.file_offset, cf.length
 		FROM chunk_files cf
@@ -71,7 +86,9 @@ func (r *ChunkFileRepository) GetByFilePath(ctx context.Context, filePath string
 }
 
 // GetByFileID retrieves chunk files by file ID
-func (r *ChunkFileRepository) GetByFileID(ctx context.Context, fileID types.FileID) ([]*ChunkFile, error) {
+func (r *ChunkFileRepository) GetByFileID(
+	ctx context.Context, fileID types.FileID,
+) ([]*ChunkFile, error) {
 	query := `
 		SELECT chunk_hash, file_id, file_offset, length
 		FROM chunk_files
@@ -87,29 +104,10 @@ func (r *ChunkFileRepository) GetByFileID(ctx context.Context, fileID types.File
 	return r.scanChunkFiles(rows)
 }
 
-// scanChunkFiles is a helper that scans chunk file rows
-func (r *ChunkFileRepository) scanChunkFiles(rows *sql.Rows) ([]*ChunkFile, error) {
-	var chunkFiles []*ChunkFile
-	for rows.Next() {
-		var cf ChunkFile
-		var chunkHashStr, fileIDStr string
-		err := rows.Scan(&chunkHashStr, &fileIDStr, &cf.FileOffset, &cf.Length)
-		if err != nil {
-			return nil, fmt.Errorf("scanning chunk file: %w", err)
-		}
-		cf.ChunkHash = types.ChunkHash(chunkHashStr)
-		cf.FileID, err = types.ParseFileID(fileIDStr)
-		if err != nil {
-			return nil, fmt.Errorf("parsing file ID: %w", err)
-		}
-		chunkFiles = append(chunkFiles, &cf)
-	}
-
-	return chunkFiles, rows.Err()
-}
-
 // DeleteByFileID deletes all chunk_files entries for a given file ID
-func (r *ChunkFileRepository) DeleteByFileID(ctx context.Context, tx *sql.Tx, fileID types.FileID) error {
+func (r *ChunkFileRepository) DeleteByFileID(
+	ctx context.Context, tx *sql.Tx, fileID types.FileID,
+) error {
 	query := `DELETE FROM chunk_files WHERE file_id = ?`
 
 	var err error
@@ -127,7 +125,11 @@ func (r *ChunkFileRepository) DeleteByFileID(ctx context.Context, tx *sql.Tx, fi
 }
 
 // DeleteByFileIDs deletes all chunk_files for multiple files in a single statement.
-func (r *ChunkFileRepository) DeleteByFileIDs(ctx context.Context, tx *sql.Tx, fileIDs []types.FileID) error {
+//
+//nolint:dupl // symmetric implementation for a parallel association table
+func (r *ChunkFileRepository) DeleteByFileIDs(
+	ctx context.Context, tx *sql.Tx, fileIDs []types.FileID,
+) error {
 	if len(fileIDs) == 0 {
 		return nil
 	}
@@ -136,14 +138,15 @@ func (r *ChunkFileRepository) DeleteByFileIDs(ctx context.Context, tx *sql.Tx, f
 	const batchSize = 500
 
 	for i := 0; i < len(fileIDs); i += batchSize {
-		end := i + batchSize
-		if end > len(fileIDs) {
-			end = len(fileIDs)
-		}
+		end := min(i+batchSize, len(fileIDs))
+
 		batch := fileIDs[i:end]
 
-		query := "DELETE FROM chunk_files WHERE file_id IN (?" + repeatPlaceholder(len(batch)-1) + ")"
-		args := make([]interface{}, len(batch))
+		//nolint:gosec // G202: concatenates constant SQL and "?" placeholders only
+		query := "DELETE FROM chunk_files WHERE file_id IN (?" +
+			repeatPlaceholder(len(batch)-1) + ")"
+
+		args := make([]any, len(batch))
 		for j, id := range batch {
 			args[j] = id.String()
 		}
@@ -154,6 +157,7 @@ func (r *ChunkFileRepository) DeleteByFileIDs(ctx context.Context, tx *sql.Tx, f
 		} else {
 			_, err = r.db.ExecWithLog(ctx, query, args...)
 		}
+
 		if err != nil {
 			return fmt.Errorf("batch deleting chunk_files: %w", err)
 		}
@@ -163,30 +167,43 @@ func (r *ChunkFileRepository) DeleteByFileIDs(ctx context.Context, tx *sql.Tx, f
 }
 
 // CreateBatch inserts multiple chunk_files in a single statement for efficiency.
-func (r *ChunkFileRepository) CreateBatch(ctx context.Context, tx *sql.Tx, cfs []ChunkFile) error {
+func (r *ChunkFileRepository) CreateBatch(
+	ctx context.Context, tx *sql.Tx, cfs []ChunkFile,
+) error {
 	if len(cfs) == 0 {
 		return nil
 	}
 
-	// Each ChunkFile has 4 values, so batch at 200 to be safe with SQLite's variable limit
+	// Each chunk_files row binds this many SQL variables.
+	const chunkFileCols = 4
+
+	// Batch at 200 rows to be safe with SQLite's variable limit.
 	const batchSize = 200
 
 	for i := 0; i < len(cfs); i += batchSize {
-		end := i + batchSize
-		if end > len(cfs) {
-			end = len(cfs)
-		}
+		end := min(i+batchSize, len(cfs))
+
 		batch := cfs[i:end]
 
 		query := "INSERT INTO chunk_files (chunk_hash, file_id, file_offset, length) VALUES "
-		args := make([]interface{}, 0, len(batch)*4)
+
+		args := make([]any, 0, len(batch)*chunkFileCols)
+
+		var querySb183 strings.Builder
+
 		for j, cf := range batch {
 			if j > 0 {
-				query += ", "
+				querySb183.WriteString(", ")
 			}
-			query += "(?, ?, ?, ?)"
-			args = append(args, cf.ChunkHash.String(), cf.FileID.String(), cf.FileOffset, cf.Length)
+
+			querySb183.WriteString("(?, ?, ?, ?)")
+
+			args = append(args,
+				cf.ChunkHash.String(), cf.FileID.String(), cf.FileOffset, cf.Length)
 		}
+
+		query += querySb183.String() //nolint:gosec // G202: appends "?" placeholders only
+
 		query += " ON CONFLICT(chunk_hash, file_id) DO NOTHING"
 
 		var err error
@@ -195,6 +212,7 @@ func (r *ChunkFileRepository) CreateBatch(ctx context.Context, tx *sql.Tx, cfs [
 		} else {
 			_, err = r.db.ExecWithLog(ctx, query, args...)
 		}
+
 		if err != nil {
 			return fmt.Errorf("batch inserting chunk_files: %w", err)
 		}
@@ -202,3 +220,31 @@ func (r *ChunkFileRepository) CreateBatch(ctx context.Context, tx *sql.Tx, cfs [
 
 	return nil
 }
+
+// scanChunkFiles is a helper that scans chunk file rows.
+func (r *ChunkFileRepository) scanChunkFiles(rows *sql.Rows) ([]*ChunkFile, error) {
+	var chunkFiles []*ChunkFile
+
+	for rows.Next() {
+		var (
+			cf                      ChunkFile
+			chunkHashStr, fileIDStr string
+		)
+
+		err := rows.Scan(&chunkHashStr, &fileIDStr, &cf.FileOffset, &cf.Length)
+		if err != nil {
+			return nil, fmt.Errorf("scanning chunk file: %w", err)
+		}
+
+		cf.ChunkHash = types.ChunkHash(chunkHashStr)
+
+		cf.FileID, err = types.ParseFileID(fileIDStr)
+		if err != nil {
+			return nil, fmt.Errorf("parsing file ID: %w", err)
+		}
+
+		chunkFiles = append(chunkFiles, &cf)
+	}
+
+	return chunkFiles, rows.Err()
+}

internal/database/chunk_files_test.go

@@ -1,120 +1,139 @@
-package database
+package database_test
 
 import (
 	"context"
 	"testing"
 	"time"
 
+	"sneak.berlin/go/vaultik/internal/database"
 	"sneak.berlin/go/vaultik/internal/types"
 )
 
+const chunk4Hash = "chunk4"
+
+// verifyChunkFilePair asserts that the chunk-file rows cover both test
+// files at their expected offsets.
+func verifyChunkFilePair(
+	t *testing.T, chunkFiles []*database.ChunkFile,
+	file1ID, file2ID types.FileID,
+) {
+	t.Helper()
+
+	foundFile1 := false
+	foundFile2 := false
+
+	for _, cf := range chunkFiles {
+		if cf.FileID == file1ID && cf.FileOffset == 0 {
+			foundFile1 = true
+		}
+
+		if cf.FileID == file2ID && cf.FileOffset == 2048 {
+			foundFile2 = true
+		}
+	}
+
+	if !foundFile1 || !foundFile2 {
+		t.Error("not all expected files found")
+	}
+}
+
+// createChunkFileTestFiles creates the two files used by the chunk-file
+// repository tests.
+func createChunkFileTestFiles(
+	t *testing.T, fileRepo *database.FileRepository,
+) (*database.File, *database.File) {
+	t.Helper()
+
+	testTime := time.Now().Truncate(time.Second)
+	file1 := &database.File{
+		Path:       testFilePath1,
+		MTime:      testTime,
+		Size:       1024,
+		Mode:       0644,
+		UID:        1000,
+		GID:        1000,
+		LinkTarget: "",
+	}
+	file2 := &database.File{
+		Path:       testFilePath2,
+		MTime:      testTime,
+		Size:       1024,
+		Mode:       0644,
+		UID:        1000,
+		GID:        1000,
+		LinkTarget: "",
+	}
+
+	mustCreateFile(t, fileRepo, file1)
+	mustCreateFile(t, fileRepo, file2)
+
+	return file1, file2
+}
+
 func TestChunkFileRepository(t *testing.T) {
+	t.Parallel()
+
 	db, cleanup := setupTestDB(t)
 	defer cleanup()
 
 	ctx := context.Background()
-	repo := NewChunkFileRepository(db)
-	fileRepo := NewFileRepository(db)
-	chunksRepo := NewChunkRepository(db)
+	repo := database.NewChunkFileRepository(db)
+	fileRepo := database.NewFileRepository(db)
+	repos := database.NewRepositories(db)
 
-	// Create test files first
-	testTime := time.Now().Truncate(time.Second)
-	file1 := &File{
-		Path:       "/file1.txt",
-		MTime:      testTime,
-		Size:       1024,
-		Mode:       0644,
-		UID:        1000,
-		GID:        1000,
-		LinkTarget: "",
-	}
-	err := fileRepo.Create(ctx, nil, file1)
-	if err != nil {
-		t.Fatalf("failed to create file1: %v", err)
-	}
-
-	file2 := &File{
-		Path:       "/file2.txt",
-		MTime:      testTime,
-		Size:       1024,
-		Mode:       0644,
-		UID:        1000,
-		GID:        1000,
-		LinkTarget: "",
-	}
-	err = fileRepo.Create(ctx, nil, file2)
-	if err != nil {
-		t.Fatalf("failed to create file2: %v", err)
-	}
-
-	// Create chunk first
-	chunk := &Chunk{
-		ChunkHash: types.ChunkHash("chunk1"),
-		Size:      1024,
-	}
-	err = chunksRepo.Create(ctx, nil, chunk)
-	if err != nil {
-		t.Fatalf("failed to create chunk: %v", err)
-	}
+	file1, file2 := createChunkFileTestFiles(t, fileRepo)
+	mustCreateChunks(t, repos, chunk1Hash)
 
 	// Test Create
-	cf1 := &ChunkFile{
-		ChunkHash:  types.ChunkHash("chunk1"),
+	cf1 := &database.ChunkFile{
+		ChunkHash:  types.ChunkHash(chunk1Hash),
 		FileID:     file1.ID,
 		FileOffset: 0,
 		Length:     1024,
 	}
 
-	err = repo.Create(ctx, nil, cf1)
+	err := repo.Create(ctx, nil, cf1)
 	if err != nil {
 		t.Fatalf("failed to create chunk file: %v", err)
 	}
 
 	// Add same chunk in different file (deduplication scenario)
-	cf2 := &ChunkFile{
-		ChunkHash:  types.ChunkHash("chunk1"),
+	cf2 := &database.ChunkFile{
+		ChunkHash:  types.ChunkHash(chunk1Hash),
 		FileID:     file2.ID,
 		FileOffset: 2048,
 		Length:     1024,
 	}
+
 	err = repo.Create(ctx, nil, cf2)
 	if err != nil {
 		t.Fatalf("failed to create second chunk file: %v", err)
 	}
 
 	// Test GetByChunkHash
-	chunkFiles, err := repo.GetByChunkHash(ctx, "chunk1")
+	chunkFiles, err := repo.GetByChunkHash(ctx, chunk1Hash)
 	if err != nil {
 		t.Fatalf("failed to get chunk files: %v", err)
 	}
+
 	if len(chunkFiles) != 2 {
 		t.Errorf("expected 2 files for chunk, got %d", len(chunkFiles))
 	}
 
 	// Verify both files are returned
-	foundFile1 := false
-	foundFile2 := false
-	for _, cf := range chunkFiles {
-		if cf.FileID == file1.ID && cf.FileOffset == 0 {
-			foundFile1 = true
-		}
-		if cf.FileID == file2.ID && cf.FileOffset == 2048 {
-			foundFile2 = true
-		}
-	}
-	if !foundFile1 || !foundFile2 {
-		t.Error("not all expected files found")
-	}
+	verifyChunkFilePair(t, chunkFiles, file1.ID, file2.ID)
 
 	// Test GetByFileID
 	chunkFiles, err = repo.GetByFileID(ctx, file1.ID)
 	if err != nil {
 		t.Fatalf("failed to get chunks by file ID: %v", err)
 	}
+
 	if len(chunkFiles) != 1 {
 		t.Errorf("expected 1 chunk for file, got %d", len(chunkFiles))
 	}
-	if chunkFiles[0].ChunkHash != types.ChunkHash("chunk1") {
+
+	if chunkFiles[0].ChunkHash != types.ChunkHash(chunk1Hash) {
 		t.Errorf("wrong chunk hash: expected chunk1, got %s", chunkFiles[0].ChunkHash)
 	}
 
@@ -126,60 +145,53 @@ func TestChunkFileRepository(t *testing.T) {
 }
 
 func TestChunkFileRepositoryComplexDeduplication(t *testing.T) {
+	t.Parallel()
+
 	db, cleanup := setupTestDB(t)
 	defer cleanup()
 
 	ctx := context.Background()
-	repo := NewChunkFileRepository(db)
-	fileRepo := NewFileRepository(db)
-	chunksRepo := NewChunkRepository(db)
+	repo := database.NewChunkFileRepository(db)
+	fileRepo := database.NewFileRepository(db)
+	repos := database.NewRepositories(db)
 
 	// Create test files
 	testTime := time.Now().Truncate(time.Second)
-	file1 := &File{Path: "/file1.txt", MTime: testTime, Size: 3072, Mode: 0644, UID: 1000, GID: 1000}
-	file2 := &File{Path: "/file2.txt", MTime: testTime, Size: 3072, Mode: 0644, UID: 1000, GID: 1000}
-	file3 := &File{Path: "/file3.txt", MTime: testTime, Size: 2048, Mode: 0644, UID: 1000, GID: 1000}
-
-	if err := fileRepo.Create(ctx, nil, file1); err != nil {
-		t.Fatalf("failed to create file1: %v", err)
+	file1 := &database.File{
+		Path: testFilePath1, MTime: testTime, Size: 3072,
+		Mode: 0644, UID: 1000, GID: 1000,
 	}
-	if err := fileRepo.Create(ctx, nil, file2); err != nil {
-		t.Fatalf("failed to create file2: %v", err)
+	file2 := &database.File{
+		Path: testFilePath2, MTime: testTime, Size: 3072,
+		Mode: 0644, UID: 1000, GID: 1000,
 	}
-	if err := fileRepo.Create(ctx, nil, file3); err != nil {
-		t.Fatalf("failed to create file3: %v", err)
+	file3 := &database.File{
+		Path: "/file3.txt", MTime: testTime, Size: 2048,
+		Mode: 0644, UID: 1000, GID: 1000,
 	}
 
-	// Create chunks first
-	chunks := []types.ChunkHash{"chunk1", "chunk2", "chunk3", "chunk4"}
-	for _, chunkHash := range chunks {
-		chunk := &Chunk{
-			ChunkHash: chunkHash,
-			Size:      1024,
-		}
-		err := chunksRepo.Create(ctx, nil, chunk)
-		if err != nil {
-			t.Fatalf("failed to create chunk %s: %v", chunkHash, err)
-		}
-	}
+	mustCreateFile(t, fileRepo, file1)
+	mustCreateFile(t, fileRepo, file2)
+	mustCreateFile(t, fileRepo, file3)
+	mustCreateChunks(t, repos, chunk1Hash, chunk2Hash, chunk3Hash, chunk4Hash)
 
 	// Simulate a scenario where multiple files share chunks
 	// File1: chunk1, chunk2, chunk3
 	// File2: chunk2, chunk3, chunk4
 	// File3: chunk1, chunk4
 
-	chunkFiles := []ChunkFile{
+	chunkFiles := []database.ChunkFile{
 		// File1
-		{ChunkHash: types.ChunkHash("chunk1"), FileID: file1.ID, FileOffset: 0, Length: 1024},
-		{ChunkHash: types.ChunkHash("chunk2"), FileID: file1.ID, FileOffset: 1024, Length: 1024},
-		{ChunkHash: types.ChunkHash("chunk3"), FileID: file1.ID, FileOffset: 2048, Length: 1024},
+		{ChunkHash: chunk1Hash, FileID: file1.ID, FileOffset: 0, Length: 1024},
+		{ChunkHash: chunk2Hash, FileID: file1.ID, FileOffset: 1024, Length: 1024},
+		{ChunkHash: chunk3Hash, FileID: file1.ID, FileOffset: 2048, Length: 1024},
 		// File2
-		{ChunkHash: types.ChunkHash("chunk2"), FileID: file2.ID, FileOffset: 0, Length: 1024},
-		{ChunkHash: types.ChunkHash("chunk3"), FileID: file2.ID, FileOffset: 1024, Length: 1024},
-		{ChunkHash: types.ChunkHash("chunk4"), FileID: file2.ID, FileOffset: 2048, Length: 1024},
+		{ChunkHash: chunk2Hash, FileID: file2.ID, FileOffset: 0, Length: 1024},
+		{ChunkHash: chunk3Hash, FileID: file2.ID, FileOffset: 1024, Length: 1024},
+		{ChunkHash: chunk4Hash, FileID: file2.ID, FileOffset: 2048, Length: 1024},
 		// File3
-		{ChunkHash: types.ChunkHash("chunk1"), FileID: file3.ID, FileOffset: 0, Length: 1024},
-		{ChunkHash: types.ChunkHash("chunk4"), FileID: file3.ID, FileOffset: 1024, Length: 1024},
+		{ChunkHash: chunk1Hash, FileID: file3.ID, FileOffset: 0, Length: 1024},
+		{ChunkHash: chunk4Hash, FileID: file3.ID, FileOffset: 1024, Length: 1024},
 	}
 
 	for _, cf := range chunkFiles {
@@ -190,19 +202,21 @@ func TestChunkFileRepositoryComplexDeduplication(t *testing.T) {
 	}
 
 	// Test chunk1 (used by file1 and file3)
-	files, err := repo.GetByChunkHash(ctx, "chunk1")
+	files, err := repo.GetByChunkHash(ctx, chunk1Hash)
 	if err != nil {
 		t.Fatalf("failed to get files for chunk1: %v", err)
 	}
+
 	if len(files) != 2 {
 		t.Errorf("expected 2 files for chunk1, got %d", len(files))
 	}
 
 	// Test chunk2 (used by file1 and file2)
-	files, err = repo.GetByChunkHash(ctx, "chunk2")
+	files, err = repo.GetByChunkHash(ctx, chunk2Hash)
 	if err != nil {
 		t.Fatalf("failed to get files for chunk2: %v", err)
 	}
+
 	if len(files) != 2 {
 		t.Errorf("expected 2 files for chunk2, got %d", len(files))
 	}
@@ -212,6 +226,7 @@ func TestChunkFileRepositoryComplexDeduplication(t *testing.T) {
 	if err != nil {
 		t.Fatalf("failed to get chunks for file2: %v", err)
 	}
+
 	if len(file2Chunks) != 3 {
 		t.Errorf("expected 3 chunks for file2, got %d", len(file2Chunks))
 	}

internal/database/chunks.go

@@ -3,19 +3,25 @@ package database
 import (
 	"context"
 	"database/sql"
+	"errors"
 	"fmt"
+	"strings"
 
 	"sneak.berlin/go/vaultik/internal/log"
 )
 
+// ChunkRepository provides access to the chunks table, which tracks
+// content-defined chunks by hash and size.
 type ChunkRepository struct {
 	db *DB
 }
 
+// NewChunkRepository creates a ChunkRepository backed by db.
 func NewChunkRepository(db *DB) *ChunkRepository {
 	return &ChunkRepository{db: db}
 }
 
+// Create inserts a chunk row (idempotently), using tx when non-nil.
 func (r *ChunkRepository) Create(ctx context.Context, tx *sql.Tx, chunk *Chunk) error {
 	query := `
 		INSERT INTO chunks (chunk_hash, size)
@@ -37,6 +43,8 @@ func (r *ChunkRepository) Create(ctx context.Context, tx *sql.Tx, chunk *Chunk)
 	return nil
 }
 
+// GetByHash returns the chunk with the given hash, or nil if it is not
+// known to the index.
 func (r *ChunkRepository) GetByHash(ctx context.Context, hash string) (*Chunk, error) {
 	query := `
 		SELECT chunk_hash, size
@@ -51,9 +59,10 @@ func (r *ChunkRepository) GetByHash(ctx context.Context, hash string) (*Chunk, e
 		&chunk.Size,
 	)
 
-	if err == sql.ErrNoRows {
-		return nil, nil
+	if errors.Is(err, sql.ErrNoRows) {
+		return nil, nil //nolint:nilnil // nil,nil signals not-found; callers check nil
 	}
+
 	if err != nil {
 		return nil, fmt.Errorf("querying chunk: %w", err)
 	}
@@ -61,7 +70,11 @@ func (r *ChunkRepository) GetByHash(ctx context.Context, hash string) (*Chunk, e
 	return &chunk, nil
 }
 
-func (r *ChunkRepository) GetByHashes(ctx context.Context, hashes []string) ([]*Chunk, error) {
+// GetByHashes returns the chunks whose hashes appear in hashes, ordered by
+// chunk hash. Unknown hashes are silently omitted from the result.
+func (r *ChunkRepository) GetByHashes(
+	ctx context.Context, hashes []string,
+) ([]*Chunk, error) {
 	if len(hashes) == 0 {
 		return nil, nil
 	}
@@ -71,14 +84,22 @@ func (r *ChunkRepository) GetByHashes(ctx context.Context, hashes []string) ([]*
 		FROM chunks
 		WHERE chunk_hash IN (`
 
-	args := make([]interface{}, len(hashes))
+	args := make([]any, len(hashes))
+
+	var querySb75 strings.Builder
+
 	for i, hash := range hashes {
 		if i > 0 {
-			query += ", "
+			querySb75.WriteString(", ")
 		}
-		query += "?"
+
+		querySb75.WriteString("?")
+
 		args[i] = hash
 	}
+
+	query += querySb75.String() //nolint:gosec // G202: appends "?" placeholders only
+
 	query += ") ORDER BY chunk_hash"
 
 	rows, err := r.db.conn.QueryContext(ctx, query, args...)
@@ -88,6 +109,7 @@ func (r *ChunkRepository) GetByHashes(ctx context.Context, hashes []string) ([]*
 	defer CloseRows(rows)
 
 	var chunks []*Chunk
+
 	for rows.Next() {
 		var chunk Chunk
 
@@ -105,7 +127,11 @@ func (r *ChunkRepository) GetByHashes(ctx context.Context, hashes []string) ([]*
 	return chunks, rows.Err()
 }
 
-func (r *ChunkRepository) ListUnpacked(ctx context.Context, limit int) ([]*Chunk, error) {
+// ListUnpacked returns up to limit chunks that are not yet stored in any
+// blob, ordered by chunk hash.
+func (r *ChunkRepository) ListUnpacked(
+	ctx context.Context, limit int,
+) ([]*Chunk, error) {
 	query := `
 		SELECT c.chunk_hash, c.size
 		FROM chunks c
@@ -122,6 +148,7 @@ func (r *ChunkRepository) ListUnpacked(ctx context.Context, limit int) ([]*Chunk
 	defer CloseRows(rows)
 
 	var chunks []*Chunk
+
 	for rows.Next() {
 		var chunk Chunk
 

internal/database/chunks_ext.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 )
 
+// List returns every chunk in the index, ordered by chunk hash.
 func (r *ChunkRepository) List(ctx context.Context) ([]*Chunk, error) {
 	query := `
 		SELECT chunk_hash, size
@@ -19,6 +20,7 @@ func (r *ChunkRepository) List(ctx context.Context) ([]*Chunk, error) {
 	defer CloseRows(rows)
 
 	var chunks []*Chunk
+
 	for rows.Next() {
 		var chunk Chunk
 

internal/database/chunks_test.go

@@ -1,21 +1,24 @@
-package database
+package database_test
 
 import (
 	"context"
 	"testing"
 
+	"sneak.berlin/go/vaultik/internal/database"
 	"sneak.berlin/go/vaultik/internal/types"
 )
 
 func TestChunkRepository(t *testing.T) {
+	t.Parallel()
+
 	db, cleanup := setupTestDB(t)
 	defer cleanup()
 
 	ctx := context.Background()
-	repo := NewChunkRepository(db)
+	repo := database.NewChunkRepository(db)
 
 	// Test Create
-	chunk := &Chunk{
+	chunk := &database.Chunk{
 		ChunkHash: types.ChunkHash("chunkhash123"),
 		Size:      4096,
 	}
@@ -30,12 +33,15 @@ func TestChunkRepository(t *testing.T) {
 	if err != nil {
 		t.Fatalf("failed to get chunk: %v", err)
 	}
+
 	if retrieved == nil {
 		t.Fatal("expected chunk, got nil")
 	}
+
 	if retrieved.ChunkHash != chunk.ChunkHash {
 		t.Errorf("chunk hash mismatch: got %s, want %s", retrieved.ChunkHash, chunk.ChunkHash)
 	}
+
 	if retrieved.Size != chunk.Size {
 		t.Errorf("size mismatch: got %d, want %d", retrieved.Size, chunk.Size)
 	}
@@ -47,19 +53,23 @@ func TestChunkRepository(t *testing.T) {
 	}
 
 	// Test GetByHashes
-	chunk2 := &Chunk{
+	chunk2 := &database.Chunk{
 		ChunkHash: types.ChunkHash("chunkhash456"),
 		Size:      8192,
 	}
+
 	err = repo.Create(ctx, nil, chunk2)
 	if err != nil {
 		t.Fatalf("failed to create second chunk: %v", err)
 	}
 
-	chunks, err := repo.GetByHashes(ctx, []string{chunk.ChunkHash.String(), chunk2.ChunkHash.String()})
+	chunks, err := repo.GetByHashes(ctx, []string{
+		chunk.ChunkHash.String(), chunk2.ChunkHash.String(),
+	})
 	if err != nil {
 		t.Fatalf("failed to get chunks by hashes: %v", err)
 	}
+
 	if len(chunks) != 2 {
 		t.Errorf("expected 2 chunks, got %d", len(chunks))
 	}
@@ -69,23 +79,27 @@ func TestChunkRepository(t *testing.T) {
 	if err != nil {
 		t.Fatalf("failed to list unpacked chunks: %v", err)
 	}
+
 	if len(unpacked) != 2 {
 		t.Errorf("expected 2 unpacked chunks, got %d", len(unpacked))
 	}
 }
 
 func TestChunkRepositoryNotFound(t *testing.T) {
+	t.Parallel()
+
 	db, cleanup := setupTestDB(t)
 	defer cleanup()
 
 	ctx := context.Background()
-	repo := NewChunkRepository(db)
+	repo := database.NewChunkRepository(db)
 
 	// Test GetByHash with non-existent hash
 	chunk, err := repo.GetByHash(ctx, "nonexistent")
 	if err != nil {
 		t.Fatalf("unexpected error: %v", err)
 	}
+
 	if chunk != nil {
 		t.Error("expected nil for non-existent chunk")
 	}
@@ -95,6 +109,7 @@ func TestChunkRepositoryNotFound(t *testing.T) {
 	if err != nil {
 		t.Fatalf("unexpected error: %v", err)
 	}
+
 	if chunks != nil {
 		t.Error("expected nil for empty hash list")
 	}

internal/database/database.go

@@ -15,6 +15,7 @@ import (
 	"context"
 	"database/sql"
 	"embed"
+	"errors"
 	"fmt"
 	"os"
 	"path/filepath"
@@ -22,10 +23,15 @@ import (
 	"strconv"
 	"strings"
 
+	// Register the pure-Go sqlite driver.
 	_ "modernc.org/sqlite"
 	"sneak.berlin/go/vaultik/internal/log"
 )
 
+// errInvalidMigrationFilename is returned when an embedded migration file
+// does not follow the "<version>[_<description>].sql" naming pattern.
+var errInvalidMigrationFilename = errors.New("invalid migration filename")
+
 //go:embed schema/*.sql
 var schemaFS embed.FS
 
@@ -51,26 +57,28 @@ type DB struct {
 func ParseMigrationVersion(filename string) (int, error) {
 	name := strings.TrimSuffix(filename, filepath.Ext(filename))
 	if name == "" {
-		return 0, fmt.Errorf("invalid migration filename %q: empty name", filename)
+		return 0, fmt.Errorf("%w %q: empty name", errInvalidMigrationFilename, filename)
 	}
 
 	// Split on underscore to separate version from description.
 	// If there's no underscore, the entire stem is the version.
 	versionStr := name
-	if idx := strings.IndexByte(name, '_'); idx >= 0 {
-		versionStr = name[:idx]
+	if before, _, ok := strings.Cut(name, "_"); ok {
+		versionStr = before
 	}
 
 	if versionStr == "" {
-		return 0, fmt.Errorf("invalid migration filename %q: empty version prefix", filename)
+		return 0, fmt.Errorf(
+			"%w %q: empty version prefix", errInvalidMigrationFilename, filename,
+		)
 	}
 
 	// Validate the version is purely numeric.
 	for _, ch := range versionStr {
 		if ch < '0' || ch > '9' {
 			return 0, fmt.Errorf(
-				"invalid migration filename %q: version %q contains non-numeric character %q",
-				filename, versionStr, string(ch),
+				"%w %q: version %q contains non-numeric character %q",
+				errInvalidMigrationFilename, filename, versionStr, string(ch),
 			)
 		}
 	}
@@ -98,61 +106,93 @@ func New(ctx context.Context, path string) (*DB, error) {
 
 	// First attempt with standard WAL mode
 	log.Debug("Attempting to open database with WAL mode", "path", path)
+
 	conn, err := sql.Open(
 		"sqlite",
-		path+"?_journal_mode=WAL&_synchronous=NORMAL&_busy_timeout=10000&_locking_mode=NORMAL&_foreign_keys=ON",
+		path+"?_journal_mode=WAL&_synchronous=NORMAL&_busy_timeout=10000"+
+			"&_locking_mode=NORMAL&_foreign_keys=ON",
 	)
 	if err == nil {
-		// Set connection pool settings
-		// SQLite can handle multiple readers but only one writer at a time.
-		// Setting MaxOpenConns to 1 ensures all writes are serialized through
-		// a single connection, preventing SQLITE_BUSY errors.
-		conn.SetMaxOpenConns(1)
-		conn.SetMaxIdleConns(1)
+		configureConnPool(conn)
 
-		if err := conn.PingContext(ctx); err == nil {
+		err = conn.PingContext(ctx)
+		if err == nil {
 			// Success on first try
 			log.Debug("Database opened successfully with WAL mode", "path", path)
 
-			// Enable foreign keys explicitly
-			if _, err := conn.ExecContext(ctx, "PRAGMA foreign_keys = ON"); err != nil {
-				log.Warn("Failed to enable foreign keys", "error", err)
+			return finishOpen(ctx, conn, path)
 		}
 
-			db := &DB{conn: conn, path: path}
-			if err := applyMigrations(ctx, conn); err != nil {
-				_ = conn.Close()
-				return nil, fmt.Errorf("applying migrations: %w", err)
-			}
-			return db, nil
-		}
-		log.Debug("Failed to ping database, closing connection", "path", path, "error", err)
+		log.Debug(
+			"Failed to ping database, closing connection",
+			"path", path, "error", err,
+		)
+
 		_ = conn.Close()
 	}
 
 	// If first attempt failed, try with TRUNCATE mode to clear any locks
+	return openWithRecovery(ctx, path)
+}
+
+// configureConnPool serializes all database access through one connection.
+// SQLite can handle multiple readers but only one writer at a time; setting
+// MaxOpenConns to 1 ensures all writes go through a single connection,
+// preventing SQLITE_BUSY errors.
+func configureConnPool(conn *sql.DB) {
+	conn.SetMaxOpenConns(1)
+	conn.SetMaxIdleConns(1)
+}
+
+// finishOpen enables foreign keys, wraps the connection, and applies any
+// pending migrations. On migration failure the connection is closed.
+func finishOpen(ctx context.Context, conn *sql.DB, path string) (*DB, error) {
+	// Enable foreign keys explicitly
+	_, err := conn.ExecContext(ctx, "PRAGMA foreign_keys = ON")
+	if err != nil {
+		log.Warn("Failed to enable foreign keys", "path", path, "error", err)
+	}
+
+	db := &DB{conn: conn, path: path}
+
+	err = applyMigrations(ctx, conn)
+	if err != nil {
+		_ = conn.Close()
+
+		return nil, fmt.Errorf("applying migrations: %w", err)
+	}
+
+	return db, nil
+}
+
+// openWithRecovery retries opening the database in TRUNCATE journal mode to
+// clear stale locks, then switches back to WAL mode.
+func openWithRecovery(ctx context.Context, path string) (*DB, error) {
 	log.Info(
 		"Database appears locked, attempting recovery with TRUNCATE mode",
 		"path", path,
 	)
-	conn, err = sql.Open(
+
+	conn, err := sql.Open(
 		"sqlite",
-		path+"?_journal_mode=TRUNCATE&_synchronous=NORMAL&_busy_timeout=10000&_foreign_keys=ON",
+		path+"?_journal_mode=TRUNCATE&_synchronous=NORMAL&_busy_timeout=10000"+
+			"&_foreign_keys=ON",
 	)
 	if err != nil {
 		return nil, fmt.Errorf("opening database in recovery mode: %w", err)
 	}
 
-	// Set connection pool settings
-	// SQLite can handle multiple readers but only one writer at a time.
-	// Setting MaxOpenConns to 1 ensures all writes are serialized through
-	// a single connection, preventing SQLITE_BUSY errors.
-	conn.SetMaxOpenConns(1)
-	conn.SetMaxIdleConns(1)
+	configureConnPool(conn)
+
+	err = conn.PingContext(ctx)
+	if err != nil {
+		log.Debug(
+			"Failed to ping database in recovery mode, closing",
+			"path", path, "error", err,
+		)
 
-	if err := conn.PingContext(ctx); err != nil {
-		log.Debug("Failed to ping database in recovery mode, closing", "path", path, "error", err)
 		_ = conn.Close()
+
 		return nil, fmt.Errorf(
 			"database still locked after recovery attempt: %w",
 			err,
@@ -163,35 +203,44 @@ func New(ctx context.Context, path string) (*DB, error) {
 
 	// Switch back to WAL mode
 	log.Debug("Switching database back to WAL mode", "path", path)
-	if _, err := conn.ExecContext(ctx, "PRAGMA journal_mode=WAL"); err != nil {
+
+	_, err = conn.ExecContext(ctx, "PRAGMA journal_mode=WAL")
+	if err != nil {
 		log.Warn("Failed to switch back to WAL mode", "path", path, "error", err)
 	}
 
-	// Ensure foreign keys are enabled
-	if _, err := conn.ExecContext(ctx, "PRAGMA foreign_keys=ON"); err != nil {
-		log.Warn("Failed to enable foreign keys", "path", path, "error", err)
-	}
-
-	db := &DB{conn: conn, path: path}
-	if err := applyMigrations(ctx, conn); err != nil {
-		_ = conn.Close()
-		return nil, fmt.Errorf("applying migrations: %w", err)
+	db, err := finishOpen(ctx, conn, path)
+	if err != nil {
+		return nil, err
 	}
 
 	log.Debug("Database connection established successfully", "path", path)
+
 	return db, nil
 }
 
+// NewTestDB creates an in-memory SQLite database for testing purposes.
+// The database is automatically initialized with the schema and is ready
+// for use. Each call creates a new independent database instance.
+func NewTestDB() (*DB, error) {
+	return New(context.Background(), ":memory:")
+}
+
 // Close closes the database connection.
 // It ensures all pending operations are completed before closing.
 // Returns an error if the database connection cannot be closed properly.
 func (db *DB) Close() error {
 	log.Debug("Closing database connection", "path", db.path)
-	if err := db.conn.Close(); err != nil {
+
+	err := db.conn.Close()
+	if err != nil {
 		log.Error("Failed to close database", "path", db.path, "error", err)
+
 		return fmt.Errorf("failed to close database: %w", err)
 	}
+
 	log.Debug("Database connection closed successfully", "path", db.path)
+
 	return nil
 }
 
@@ -227,22 +276,25 @@ func (db *DB) BeginTx(
 func (db *DB) ExecWithLog(
 	ctx context.Context,
 	query string,
-	args ...interface{},
+	args ...any,
 ) (sql.Result, error) {
 	LogSQL("Execute", query, args...)
+
 	return db.conn.ExecContext(ctx, query, args...)
 }
 
-// QueryRowWithLog executes a query that returns at most one row with SQL logging.
-// This is useful for queries that modify data and return values (e.g., INSERT ... RETURNING).
-// SQLite handles its own locking internally.
-// The query and args parameters follow the same format as sql.DB.QueryRowContext.
+// QueryRowWithLog executes a query that returns at most one row with SQL
+// logging. This is useful for queries that modify data and return values
+// (e.g., INSERT ... RETURNING). SQLite handles its own locking internally.
+// The query and args parameters follow the same format as
+// sql.DB.QueryRowContext.
 func (db *DB) QueryRowWithLog(
 	ctx context.Context,
 	query string,
-	args ...interface{},
+	args ...any,
 ) *sql.Row {
 	LogSQL("QueryRow", query, args...)
+
 	return db.conn.QueryRowContext(ctx, query, args...)
 }
 
@@ -302,7 +354,8 @@ func bootstrapMigrationsTable(ctx context.Context, db *sql.DB) error {
 // the schema_migrations table via 000.sql, then iterates through remaining
 // migration files in order.
 func applyMigrations(ctx context.Context, db *sql.DB) error {
-	if err := bootstrapMigrationsTable(ctx, db); err != nil {
+	err := bootstrapMigrationsTable(ctx, db)
+	if err != nil {
 		return err
 	}
 
@@ -362,30 +415,26 @@ func applyMigrations(ctx context.Context, db *sql.DB) error {
 	return nil
 }
 
-// NewTestDB creates an in-memory SQLite database for testing purposes.
-// The database is automatically initialized with the schema and is ready for use.
-// Each call creates a new independent database instance.
-func NewTestDB() (*DB, error) {
-	return New(context.Background(), ":memory:")
-}
-
-// repeatPlaceholder generates a string of ", ?" repeated n times for IN clause construction.
-// For example, repeatPlaceholder(2) returns ", ?, ?".
+// repeatPlaceholder generates a string of ", ?" repeated n times for IN
+// clause construction. For example, repeatPlaceholder(2) returns ", ?, ?".
 func repeatPlaceholder(n int) string {
 	if n <= 0 {
 		return ""
 	}
+
 	return strings.Repeat(", ?", n)
 }
 
 // LogSQL logs SQL queries and their arguments when debug mode is enabled.
-// Debug mode is activated by setting the GODEBUG environment variable to include "vaultik".
-// This is useful for troubleshooting database operations and understanding query patterns.
+// Debug mode is activated by setting the GODEBUG environment variable to
+// include "vaultik". This is useful for troubleshooting database operations
+// and understanding query patterns.
 //
-// The operation parameter describes the type of SQL operation (e.g., "Execute", "Query").
-// The query parameter is the SQL statement being executed.
-// The args parameter contains the query arguments that will be interpolated.
-func LogSQL(operation, query string, args ...interface{}) {
+// The operation parameter describes the type of SQL operation (e.g.,
+// "Execute", "Query"). The query parameter is the SQL statement being
+// executed. The args parameter contains the query arguments that will be
+// interpolated.
+func LogSQL(operation, query string, args ...any) {
 	if strings.Contains(os.Getenv("GODEBUG"), "vaultik") {
 		log.Debug(
 			"SQL "+operation,

internal/database/database_test.go

@@ -1,3 +1,4 @@
+//nolint:testpackage // exercises unexported migration internals
 package database
 
 import (
@@ -9,6 +10,8 @@ import (
 )
 
 func TestDatabase(t *testing.T) {
+	t.Parallel()
+
 	ctx := context.Background()
 	dbPath := filepath.Join(t.TempDir(), "test.db")
 
@@ -17,7 +20,8 @@ func TestDatabase(t *testing.T) {
 		t.Fatalf("failed to create database: %v", err)
 	}
 	defer func() {
-		if err := db.Close(); err != nil {
+		err := db.Close()
+		if err != nil {
 			t.Errorf("failed to close database: %v", err)
 		}
 	}()
@@ -37,7 +41,10 @@ func TestDatabase(t *testing.T) {
 
 	for _, table := range tables {
 		var name string
-		err := db.conn.QueryRow("SELECT name FROM sqlite_master WHERE type='table' AND name=?", table).Scan(&name)
+
+		err := db.conn.QueryRowContext(ctx,
+			"SELECT name FROM sqlite_master WHERE type='table' AND name=?", table,
+		).Scan(&name)
 		if err != nil {
 			t.Errorf("table %s does not exist: %v", table, err)
 		}
@@ -45,6 +52,8 @@ func TestDatabase(t *testing.T) {
 }
 
 func TestDatabaseInvalidPath(t *testing.T) {
+	t.Parallel()
+
 	ctx := context.Background()
 
 	// Test with invalid path
@@ -55,6 +64,8 @@ func TestDatabaseInvalidPath(t *testing.T) {
 }
 
 func TestDatabaseConcurrentAccess(t *testing.T) {
+	t.Parallel()
+
 	ctx := context.Background()
 	dbPath := filepath.Join(t.TempDir(), "test.db")
 
@@ -63,7 +74,8 @@ func TestDatabaseConcurrentAccess(t *testing.T) {
 		t.Fatalf("failed to create database: %v", err)
 	}
 	defer func() {
-		if err := db.Close(); err != nil {
+		err := db.Close()
+		if err != nil {
 			t.Errorf("failed to close database: %v", err)
 		}
 	}()
@@ -73,18 +85,20 @@ func TestDatabaseConcurrentAccess(t *testing.T) {
 		index int
 		err   error
 	}
+
 	results := make(chan result, 10)
 
-	for i := 0; i < 10; i++ {
+	for i := range 10 {
 		go func(i int) {
-			_, err := db.ExecWithLog(ctx, "INSERT INTO chunks (chunk_hash, size) VALUES (?, ?)",
+			_, err := db.ExecWithLog(ctx,
+				"INSERT INTO chunks (chunk_hash, size) VALUES (?, ?)",
 				fmt.Sprintf("hash%d", i), i*1024)
 			results <- result{index: i, err: err}
 		}(i)
 	}
 
 	// Wait for all goroutines and check results
-	for i := 0; i < 10; i++ {
+	for range 10 {
 		r := <-results
 		if r.err != nil {
 			t.Fatalf("concurrent insert %d failed: %v", r.index, r.err)
@@ -93,16 +107,20 @@ func TestDatabaseConcurrentAccess(t *testing.T) {
 
 	// Verify all inserts succeeded
 	var count int
+
 	err = db.conn.QueryRowContext(ctx, "SELECT COUNT(*) FROM chunks").Scan(&count)
 	if err != nil {
 		t.Fatalf("failed to count chunks: %v", err)
 	}
+
 	if count != 10 {
 		t.Errorf("expected 10 chunks, got %d", count)
 	}
 }
 
 func TestParseMigrationVersion(t *testing.T) {
+	t.Parallel()
+
 	tests := []struct {
 		name      string
 		filename  string
@@ -112,8 +130,14 @@ func TestParseMigrationVersion(t *testing.T) {
 		{name: "valid 000.sql", filename: "000.sql", wantVer: 0, wantError: false},
 		{name: "valid 001.sql", filename: "001.sql", wantVer: 1, wantError: false},
 		{name: "valid 099.sql", filename: "099.sql", wantVer: 99, wantError: false},
-		{name: "valid with description", filename: "001_initial_schema.sql", wantVer: 1, wantError: false},
-		{name: "valid large version", filename: "123_big_migration.sql", wantVer: 123, wantError: false},
+		{
+			name: "valid with description", filename: "001_initial_schema.sql",
+			wantVer: 1, wantError: false,
+		},
+		{
+			name: "valid large version", filename: "123_big_migration.sql",
+			wantVer: 123, wantError: false,
+		},
 		{name: "invalid alpha version", filename: "abc.sql", wantVer: 0, wantError: true},
 		{name: "invalid mixed chars", filename: "12a.sql", wantVer: 0, wantError: true},
 		{name: "invalid no extension", filename: "schema.sql", wantVer: 0, wantError: true},
@@ -122,25 +146,36 @@ func TestParseMigrationVersion(t *testing.T) {
 
 	for _, tc := range tests {
 		t.Run(tc.name, func(t *testing.T) {
+			t.Parallel()
+
 			got, err := ParseMigrationVersion(tc.filename)
 			if tc.wantError {
 				if err == nil {
-					t.Errorf("ParseMigrationVersion(%q) = %d, nil; want error", tc.filename, got)
+					t.Errorf("ParseMigrationVersion(%q) = %d, nil; want error",
+						tc.filename, got)
 				}
+
 				return
 			}
+
 			if err != nil {
-				t.Errorf("ParseMigrationVersion(%q) unexpected error: %v", tc.filename, err)
+				t.Errorf("ParseMigrationVersion(%q) unexpected error: %v",
+					tc.filename, err)
+
 				return
 			}
+
 			if got != tc.wantVer {
-				t.Errorf("ParseMigrationVersion(%q) = %d; want %d", tc.filename, got, tc.wantVer)
+				t.Errorf("ParseMigrationVersion(%q) = %d; want %d",
+					tc.filename, got, tc.wantVer)
 			}
 		})
 	}
 }
 
 func TestApplyMigrations_Idempotent(t *testing.T) {
+	t.Parallel()
+
 	ctx := context.Background()
 
 	conn, err := sql.Open("sqlite", ":memory:?_foreign_keys=ON")
@@ -148,7 +183,8 @@ func TestApplyMigrations_Idempotent(t *testing.T) {
 		t.Fatalf("failed to open database: %v", err)
 	}
 	defer func() {
-		if err := conn.Close(); err != nil {
+		err := conn.Close()
+		if err != nil {
 			t.Errorf("failed to close database: %v", err)
 		}
 	}()
@@ -157,33 +193,46 @@ func TestApplyMigrations_Idempotent(t *testing.T) {
 	conn.SetMaxIdleConns(1)
 
 	// First run: apply all migrations.
-	if err := applyMigrations(ctx, conn); err != nil {
+	err = applyMigrations(ctx, conn)
+	if err != nil {
 		t.Fatalf("first applyMigrations failed: %v", err)
 	}
 
 	// Count rows in schema_migrations after first run.
 	var countBefore int
-	if err := conn.QueryRowContext(ctx, "SELECT COUNT(*) FROM schema_migrations").Scan(&countBefore); err != nil {
+
+	err = conn.QueryRowContext(ctx,
+		"SELECT COUNT(*) FROM schema_migrations",
+	).Scan(&countBefore)
+	if err != nil {
 		t.Fatalf("failed to count schema_migrations after first run: %v", err)
 	}
 
 	// Second run: must be a no-op.
-	if err := applyMigrations(ctx, conn); err != nil {
+	err = applyMigrations(ctx, conn)
+	if err != nil {
 		t.Fatalf("second applyMigrations failed: %v", err)
 	}
 
 	// Count rows in schema_migrations after second run — must be unchanged.
 	var countAfter int
-	if err := conn.QueryRowContext(ctx, "SELECT COUNT(*) FROM schema_migrations").Scan(&countAfter); err != nil {
+
+	err = conn.QueryRowContext(ctx,
+		"SELECT COUNT(*) FROM schema_migrations",
+	).Scan(&countAfter)
+	if err != nil {
 		t.Fatalf("failed to count schema_migrations after second run: %v", err)
 	}
 
 	if countBefore != countAfter {
-		t.Errorf("schema_migrations row count changed: before=%d, after=%d", countBefore, countAfter)
+		t.Errorf("schema_migrations row count changed: before=%d, after=%d",
+			countBefore, countAfter)
 	}
 }
 
 func TestBootstrapMigrationsTable_FreshDatabase(t *testing.T) {
+	t.Parallel()
+
 	ctx := context.Background()
 
 	conn, err := sql.Open("sqlite", ":memory:?_foreign_keys=ON")
@@ -191,7 +240,8 @@ func TestBootstrapMigrationsTable_FreshDatabase(t *testing.T) {
 		t.Fatalf("failed to open database: %v", err)
 	}
 	defer func() {
-		if err := conn.Close(); err != nil {
+		err := conn.Close()
+		if err != nil {
 			t.Errorf("failed to close database: %v", err)
 		}
 	}()
@@ -201,38 +251,49 @@ func TestBootstrapMigrationsTable_FreshDatabase(t *testing.T) {
 
 	// Verify schema_migrations does NOT exist yet.
 	var tableBefore int
-	if err := conn.QueryRowContext(ctx,
+
+	err = conn.QueryRowContext(ctx,
 		"SELECT COUNT(*) FROM sqlite_master WHERE type='table' AND name='schema_migrations'",
-	).Scan(&tableBefore); err != nil {
+	).Scan(&tableBefore)
+	if err != nil {
 		t.Fatalf("failed to check for table before bootstrap: %v", err)
 	}
+
 	if tableBefore != 0 {
 		t.Fatal("schema_migrations table should not exist before bootstrap")
 	}
 
 	// Run bootstrap.
-	if err := bootstrapMigrationsTable(ctx, conn); err != nil {
+	err = bootstrapMigrationsTable(ctx, conn)
+	if err != nil {
 		t.Fatalf("bootstrapMigrationsTable failed: %v", err)
 	}
 
 	// Verify schema_migrations now exists.
 	var tableAfter int
-	if err := conn.QueryRowContext(ctx,
+
+	err = conn.QueryRowContext(ctx,
 		"SELECT COUNT(*) FROM sqlite_master WHERE type='table' AND name='schema_migrations'",
-	).Scan(&tableAfter); err != nil {
+	).Scan(&tableAfter)
+	if err != nil {
 		t.Fatalf("failed to check for table after bootstrap: %v", err)
 	}
+
 	if tableAfter != 1 {
-		t.Fatalf("schema_migrations table should exist after bootstrap, got count=%d", tableAfter)
+		t.Fatalf("schema_migrations table should exist after bootstrap, got count=%d",
+			tableAfter)
 	}
 
 	// Verify version 0 row exists.
 	var version int
-	if err := conn.QueryRowContext(ctx,
+
+	err = conn.QueryRowContext(ctx,
 		"SELECT version FROM schema_migrations WHERE version = 0",
-	).Scan(&version); err != nil {
+	).Scan(&version)
+	if err != nil {
 		t.Fatalf("version 0 row not found in schema_migrations: %v", err)
 	}
+
 	if version != 0 {
 		t.Errorf("expected version 0, got %d", version)
 	}

internal/database/errors.go

@@ -6,15 +6,16 @@ import (
 	"os"
 )
 
-// Fatal prints an error message to stderr and exits with status 1
-func Fatal(format string, args ...interface{}) {
+// Fatalf prints an error message to stderr and exits with status 1
+func Fatalf(format string, args ...any) {
 	fmt.Fprintf(os.Stderr, "FATAL: "+format+"\n", args...)
 	os.Exit(1)
 }
 
 // CloseRows closes rows and exits on error
 func CloseRows(rows *sql.Rows) {
-	if err := rows.Close(); err != nil {
-		Fatal("failed to close rows: %v", err)
+	err := rows.Close()
+	if err != nil {
+		Fatalf("failed to close rows: %v", err)
 	}
 }

internal/database/file_chunks.go

@@ -4,19 +4,26 @@ import (
 	"context"
 	"database/sql"
 	"fmt"
+	"strings"
 
 	"sneak.berlin/go/vaultik/internal/types"
 )
 
+// FileChunkRepository provides access to the file_chunks table, which maps
+// files to their ordered constituent chunks.
 type FileChunkRepository struct {
 	db *DB
 }
 
+// NewFileChunkRepository creates a FileChunkRepository backed by db.
 func NewFileChunkRepository(db *DB) *FileChunkRepository {
 	return &FileChunkRepository{db: db}
 }
 
-func (r *FileChunkRepository) Create(ctx context.Context, tx *sql.Tx, fc *FileChunk) error {
+// Create inserts a file_chunks row (idempotently), using tx when non-nil.
+func (r *FileChunkRepository) Create(
+	ctx context.Context, tx *sql.Tx, fc *FileChunk,
+) error {
 	query := `
 		INSERT INTO file_chunks (file_id, idx, chunk_hash)
 		VALUES (?, ?, ?)
@@ -27,7 +34,8 @@ func (r *FileChunkRepository) Create(ctx context.Context, tx *sql.Tx, fc *FileCh
 	if tx != nil {
 		_, err = tx.ExecContext(ctx, query, fc.FileID.String(), fc.Idx, fc.ChunkHash.String())
 	} else {
-		_, err = r.db.ExecWithLog(ctx, query, fc.FileID.String(), fc.Idx, fc.ChunkHash.String())
+		_, err = r.db.ExecWithLog(ctx, query,
+			fc.FileID.String(), fc.Idx, fc.ChunkHash.String())
 	}
 
 	if err != nil {
@@ -37,7 +45,10 @@ func (r *FileChunkRepository) Create(ctx context.Context, tx *sql.Tx, fc *FileCh
 	return nil
 }
 
-func (r *FileChunkRepository) GetByPath(ctx context.Context, path string) ([]*FileChunk, error) {
+// GetByPath returns the ordered chunks of the file at the given path.
+func (r *FileChunkRepository) GetByPath(
+	ctx context.Context, path string,
+) ([]*FileChunk, error) {
 	query := `
 		SELECT fc.file_id, fc.idx, fc.chunk_hash
 		FROM file_chunks fc
@@ -56,7 +67,9 @@ func (r *FileChunkRepository) GetByPath(ctx context.Context, path string) ([]*Fi
 }
 
 // GetByFileID retrieves file chunks by file ID
-func (r *FileChunkRepository) GetByFileID(ctx context.Context, fileID types.FileID) ([]*FileChunk, error) {
+func (r *FileChunkRepository) GetByFileID(
+	ctx context.Context, fileID types.FileID,
+) ([]*FileChunk, error) {
 	query := `
 		SELECT file_id, idx, chunk_hash
 		FROM file_chunks
@@ -74,7 +87,9 @@ func (r *FileChunkRepository) GetByFileID(ctx context.Context, fileID types.File
 }
 
 // GetByPathTx retrieves file chunks within a transaction
-func (r *FileChunkRepository) GetByPathTx(ctx context.Context, tx *sql.Tx, path string) ([]*FileChunk, error) {
+func (r *FileChunkRepository) GetByPathTx(
+	ctx context.Context, tx *sql.Tx, path string,
+) ([]*FileChunk, error) {
 	query := `
 		SELECT fc.file_id, fc.idx, fc.chunk_hash
 		FROM file_chunks fc
@@ -84,6 +99,7 @@ func (r *FileChunkRepository) GetByPathTx(ctx context.Context, tx *sql.Tx, path
 	`
 
 	LogSQL("GetByPathTx", query, path)
+
 	rows, err := tx.QueryContext(ctx, query, path)
 	if err != nil {
 		return nil, fmt.Errorf("querying file chunks: %w", err)
@@ -92,32 +108,18 @@ func (r *FileChunkRepository) GetByPathTx(ctx context.Context, tx *sql.Tx, path
 
 	fileChunks, err := r.scanFileChunks(rows)
 	LogSQL("GetByPathTx", "Complete", path, "count", len(fileChunks))
+
 	return fileChunks, err
 }
 
-// scanFileChunks is a helper that scans file chunk rows
-func (r *FileChunkRepository) scanFileChunks(rows *sql.Rows) ([]*FileChunk, error) {
-	var fileChunks []*FileChunk
-	for rows.Next() {
-		var fc FileChunk
-		var fileIDStr, chunkHashStr string
-		err := rows.Scan(&fileIDStr, &fc.Idx, &chunkHashStr)
-		if err != nil {
-			return nil, fmt.Errorf("scanning file chunk: %w", err)
-		}
-		fc.FileID, err = types.ParseFileID(fileIDStr)
-		if err != nil {
-			return nil, fmt.Errorf("parsing file ID: %w", err)
-		}
-		fc.ChunkHash = types.ChunkHash(chunkHashStr)
-		fileChunks = append(fileChunks, &fc)
-	}
-
-	return fileChunks, rows.Err()
-}
-
-func (r *FileChunkRepository) DeleteByPath(ctx context.Context, tx *sql.Tx, path string) error {
-	query := `DELETE FROM file_chunks WHERE file_id = (SELECT id FROM files WHERE path = ?)`
+// DeleteByPath deletes all file_chunks rows for the file at the given path.
+func (r *FileChunkRepository) DeleteByPath(
+	ctx context.Context, tx *sql.Tx, path string,
+) error {
+	query := `
+		DELETE FROM file_chunks
+		WHERE file_id = (SELECT id FROM files WHERE path = ?)
+	`
 
 	var err error
 	if tx != nil {
@@ -134,7 +136,9 @@ func (r *FileChunkRepository) DeleteByPath(ctx context.Context, tx *sql.Tx, path
 }
 
 // DeleteByFileID deletes all chunks for a file by its UUID
-func (r *FileChunkRepository) DeleteByFileID(ctx context.Context, tx *sql.Tx, fileID types.FileID) error {
+func (r *FileChunkRepository) DeleteByFileID(
+	ctx context.Context, tx *sql.Tx, fileID types.FileID,
+) error {
 	query := `DELETE FROM file_chunks WHERE file_id = ?`
 
 	var err error
@@ -152,7 +156,11 @@ func (r *FileChunkRepository) DeleteByFileID(ctx context.Context, tx *sql.Tx, fi
 }
 
 // DeleteByFileIDs deletes all chunks for multiple files in a single statement.
-func (r *FileChunkRepository) DeleteByFileIDs(ctx context.Context, tx *sql.Tx, fileIDs []types.FileID) error {
+//
+//nolint:dupl // symmetric implementation for a parallel association table
+func (r *FileChunkRepository) DeleteByFileIDs(
+	ctx context.Context, tx *sql.Tx, fileIDs []types.FileID,
+) error {
 	if len(fileIDs) == 0 {
 		return nil
 	}
@@ -161,14 +169,15 @@ func (r *FileChunkRepository) DeleteByFileIDs(ctx context.Context, tx *sql.Tx, f
 	const batchSize = 500
 
 	for i := 0; i < len(fileIDs); i += batchSize {
-		end := i + batchSize
-		if end > len(fileIDs) {
-			end = len(fileIDs)
-		}
+		end := min(i+batchSize, len(fileIDs))
+
 		batch := fileIDs[i:end]
 
-		query := "DELETE FROM file_chunks WHERE file_id IN (?" + repeatPlaceholder(len(batch)-1) + ")"
-		args := make([]interface{}, len(batch))
+		//nolint:gosec // G202: concatenates constant SQL and "?" placeholders only
+		query := "DELETE FROM file_chunks WHERE file_id IN (?" +
+			repeatPlaceholder(len(batch)-1) + ")"
+
+		args := make([]any, len(batch))
 		for j, id := range batch {
 			args[j] = id.String()
 		}
@@ -179,6 +188,7 @@ func (r *FileChunkRepository) DeleteByFileIDs(ctx context.Context, tx *sql.Tx, f
 		} else {
 			_, err = r.db.ExecWithLog(ctx, query, args...)
 		}
+
 		if err != nil {
 			return fmt.Errorf("batch deleting file_chunks: %w", err)
 		}
@@ -189,32 +199,44 @@ func (r *FileChunkRepository) DeleteByFileIDs(ctx context.Context, tx *sql.Tx, f
 
 // CreateBatch inserts multiple file_chunks in a single statement for efficiency.
 // Batches are automatically split to stay within SQLite's variable limit.
-func (r *FileChunkRepository) CreateBatch(ctx context.Context, tx *sql.Tx, fcs []FileChunk) error {
+func (r *FileChunkRepository) CreateBatch(
+	ctx context.Context, tx *sql.Tx, fcs []FileChunk,
+) error {
 	if len(fcs) == 0 {
 		return nil
 	}
 
-	// SQLite has a limit on variables (typically 999 or 32766).
-	// Each FileChunk has 3 values, so batch at 300 to be safe.
+	// Each file_chunks row binds this many SQL variables.
+	const fileChunkCols = 3
+
+	// SQLite has a limit on variables (typically 999 or 32766), so batch
+	// at 300 rows to be safe.
 	const batchSize = 300
 
 	for i := 0; i < len(fcs); i += batchSize {
-		end := i + batchSize
-		if end > len(fcs) {
-			end = len(fcs)
-		}
+		end := min(i+batchSize, len(fcs))
+
 		batch := fcs[i:end]
 
 		// Build the query with multiple value sets
 		query := "INSERT INTO file_chunks (file_id, idx, chunk_hash) VALUES "
-		args := make([]interface{}, 0, len(batch)*3)
+
+		args := make([]any, 0, len(batch)*fileChunkCols)
+
+		var querySb211 strings.Builder
+
 		for j, fc := range batch {
 			if j > 0 {
-				query += ", "
+				querySb211.WriteString(", ")
 			}
-			query += "(?, ?, ?)"
+
+			querySb211.WriteString("(?, ?, ?)")
+
 			args = append(args, fc.FileID.String(), fc.Idx, fc.ChunkHash.String())
 		}
+
+		query += querySb211.String() //nolint:gosec // G202: appends "?" placeholders only
+
 		query += " ON CONFLICT(file_id, idx) DO NOTHING"
 
 		var err error
@@ -223,6 +245,7 @@ func (r *FileChunkRepository) CreateBatch(ctx context.Context, tx *sql.Tx, fcs [
 		} else {
 			_, err = r.db.ExecWithLog(ctx, query, args...)
 		}
+
 		if err != nil {
 			return fmt.Errorf("batch inserting file_chunks: %w", err)
 		}
@@ -232,17 +255,50 @@ func (r *FileChunkRepository) CreateBatch(ctx context.Context, tx *sql.Tx, fcs [
 }
 
 // GetByFile is an alias for GetByPath for compatibility
-func (r *FileChunkRepository) GetByFile(ctx context.Context, path string) ([]*FileChunk, error) {
+func (r *FileChunkRepository) GetByFile(
+	ctx context.Context, path string,
+) ([]*FileChunk, error) {
 	LogSQL("GetByFile", "Starting", path)
 	result, err := r.GetByPath(ctx, path)
 	LogSQL("GetByFile", "Complete", path, "count", len(result))
+
 	return result, err
 }
 
 // GetByFileTx retrieves file chunks within a transaction
-func (r *FileChunkRepository) GetByFileTx(ctx context.Context, tx *sql.Tx, path string) ([]*FileChunk, error) {
+func (r *FileChunkRepository) GetByFileTx(
+	ctx context.Context, tx *sql.Tx, path string,
+) ([]*FileChunk, error) {
 	LogSQL("GetByFileTx", "Starting", path)
 	result, err := r.GetByPathTx(ctx, tx, path)
 	LogSQL("GetByFileTx", "Complete", path, "count", len(result))
+
 	return result, err
 }
+
+// scanFileChunks is a helper that scans file chunk rows
+func (r *FileChunkRepository) scanFileChunks(rows *sql.Rows) ([]*FileChunk, error) {
+	var fileChunks []*FileChunk
+
+	for rows.Next() {
+		var (
+			fc                      FileChunk
+			fileIDStr, chunkHashStr string
+		)
+
+		err := rows.Scan(&fileIDStr, &fc.Idx, &chunkHashStr)
+		if err != nil {
+			return nil, fmt.Errorf("scanning file chunk: %w", err)
+		}
+
+		fc.FileID, err = types.ParseFileID(fileIDStr)
+		if err != nil {
+			return nil, fmt.Errorf("parsing file ID: %w", err)
+		}
+
+		fc.ChunkHash = types.ChunkHash(chunkHashStr)
+		fileChunks = append(fileChunks, &fc)
+	}
+
+	return fileChunks, rows.Err()
+}

internal/database/file_chunks_test.go

@@ -1,4 +1,4 @@
-package database
+package database_test
 
 import (
 	"context"
@@ -6,21 +6,25 @@ import (
 	"testing"
 	"time"
 
+	"sneak.berlin/go/vaultik/internal/database"
 	"sneak.berlin/go/vaultik/internal/types"
 )
 
 func TestFileChunkRepository(t *testing.T) {
+	t.Parallel()
+
 	db, cleanup := setupTestDB(t)
 	defer cleanup()
 
 	ctx := context.Background()
-	repo := NewFileChunkRepository(db)
-	fileRepo := NewFileRepository(db)
+	repo := database.NewFileChunkRepository(db)
+	fileRepo := database.NewFileRepository(db)
+	repos := database.NewRepositories(db)
 
 	// Create test file first
 	testTime := time.Now().Truncate(time.Second)
-	file := &File{
-		Path:       "/test/file.txt",
+	file := &database.File{
+		Path:       testFileTxt,
 		MTime:      testTime,
 		Size:       3072,
 		Mode:       0644,
@@ -28,63 +32,51 @@ func TestFileChunkRepository(t *testing.T) {
 		GID:        1000,
 		LinkTarget: "",
 	}
-	err := fileRepo.Create(ctx, nil, file)
-	if err != nil {
-		t.Fatalf("failed to create file: %v", err)
-	}
 
-	// Create chunks first
-	chunks := []types.ChunkHash{"chunk1", "chunk2", "chunk3"}
-	chunkRepo := NewChunkRepository(db)
-	for _, chunkHash := range chunks {
-		chunk := &Chunk{
-			ChunkHash: chunkHash,
-			Size:      1024,
-		}
-		err = chunkRepo.Create(ctx, nil, chunk)
-		if err != nil {
-			t.Fatalf("failed to create chunk %s: %v", chunkHash, err)
-		}
-	}
+	mustCreateFile(t, fileRepo, file)
+	mustCreateChunks(t, repos, chunk1Hash, chunk2Hash, chunk3Hash)
 
 	// Test Create
-	fc1 := &FileChunk{
+	fc1 := &database.FileChunk{
 		FileID:    file.ID,
 		Idx:       0,
-		ChunkHash: types.ChunkHash("chunk1"),
+		ChunkHash: types.ChunkHash(chunk1Hash),
 	}
 
-	err = repo.Create(ctx, nil, fc1)
+	err := repo.Create(ctx, nil, fc1)
 	if err != nil {
 		t.Fatalf("failed to create file chunk: %v", err)
 	}
 
 	// Add more chunks for the same file
-	fc2 := &FileChunk{
+	fc2 := &database.FileChunk{
 		FileID:    file.ID,
 		Idx:       1,
-		ChunkHash: types.ChunkHash("chunk2"),
+		ChunkHash: types.ChunkHash(chunk2Hash),
 	}
+
 	err = repo.Create(ctx, nil, fc2)
 	if err != nil {
 		t.Fatalf("failed to create second file chunk: %v", err)
 	}
 
-	fc3 := &FileChunk{
+	fc3 := &database.FileChunk{
 		FileID:    file.ID,
 		Idx:       2,
-		ChunkHash: types.ChunkHash("chunk3"),
+		ChunkHash: types.ChunkHash(chunk3Hash),
 	}
+
 	err = repo.Create(ctx, nil, fc3)
 	if err != nil {
 		t.Fatalf("failed to create third file chunk: %v", err)
 	}
 
 	// Test GetByFile
-	fileChunks, err := repo.GetByFile(ctx, "/test/file.txt")
+	fileChunks, err := repo.GetByFile(ctx, testFileTxt)
 	if err != nil {
 		t.Fatalf("failed to get file chunks: %v", err)
 	}
+
 	if len(fileChunks) != 3 {
 		t.Errorf("expected 3 chunks, got %d", len(fileChunks))
 	}
@@ -101,6 +93,41 @@ func TestFileChunkRepository(t *testing.T) {
 	if err != nil {
 		t.Fatalf("failed to create duplicate file chunk: %v", err)
 	}
+}
+
+func TestFileChunkRepositoryDeleteByFileID(t *testing.T) {
+	t.Parallel()
+
+	db, cleanup := setupTestDB(t)
+	defer cleanup()
+
+	ctx := context.Background()
+	repo := database.NewFileChunkRepository(db)
+	fileRepo := database.NewFileRepository(db)
+	repos := database.NewRepositories(db)
+
+	file := &database.File{
+		Path:  testFileTxt,
+		MTime: time.Now().Truncate(time.Second),
+		Size:  1024,
+		Mode:  0644,
+		UID:   1000,
+		GID:   1000,
+	}
+
+	mustCreateFile(t, fileRepo, file)
+	mustCreateChunks(t, repos, chunk1Hash)
+
+	fc := &database.FileChunk{
+		FileID:    file.ID,
+		Idx:       0,
+		ChunkHash: types.ChunkHash(chunk1Hash),
+	}
+
+	err := repo.Create(ctx, nil, fc)
+	if err != nil {
+		t.Fatalf("failed to create file chunk: %v", err)
+	}
 
 	// Test DeleteByFileID
 	err = repo.DeleteByFileID(ctx, nil, file.ID)
@@ -108,30 +135,33 @@ func TestFileChunkRepository(t *testing.T) {
 		t.Fatalf("failed to delete file chunks: %v", err)
 	}
 
-	fileChunks, err = repo.GetByFileID(ctx, file.ID)
+	fileChunks, err := repo.GetByFileID(ctx, file.ID)
 	if err != nil {
 		t.Fatalf("failed to get deleted file chunks: %v", err)
 	}
+
 	if len(fileChunks) != 0 {
 		t.Errorf("expected 0 chunks after delete, got %d", len(fileChunks))
 	}
 }
 
 func TestFileChunkRepositoryMultipleFiles(t *testing.T) {
+	t.Parallel()
+
 	db, cleanup := setupTestDB(t)
 	defer cleanup()
 
 	ctx := context.Background()
-	repo := NewFileChunkRepository(db)
-	fileRepo := NewFileRepository(db)
+	repo := database.NewFileChunkRepository(db)
+	fileRepo := database.NewFileRepository(db)
 
 	// Create test files
 	testTime := time.Now().Truncate(time.Second)
-	filePaths := []string{"/file1.txt", "/file2.txt", "/file3.txt"}
-	files := make([]*File, len(filePaths))
+	filePaths := []string{testFilePath1, testFilePath2, "/file3.txt"}
+	files := make([]*database.File, len(filePaths))
 
 	for i, path := range filePaths {
-		file := &File{
+		file := &database.File{
 			Path:       types.FilePath(path),
 			MTime:      testTime,
 			Size:       2048,
@@ -140,22 +170,23 @@ func TestFileChunkRepositoryMultipleFiles(t *testing.T) {
 			GID:        1000,
 			LinkTarget: "",
 		}
-		err := fileRepo.Create(ctx, nil, file)
-		if err != nil {
-			t.Fatalf("failed to create file %s: %v", path, err)
-		}
+
+		mustCreateFile(t, fileRepo, file)
+
 		files[i] = file
 	}
 
 	// Create all chunks first
-	chunkRepo := NewChunkRepository(db)
+	chunkRepo := database.NewChunkRepository(db)
+
 	for i := range files {
-		for j := 0; j < 2; j++ {
+		for j := range 2 {
 			chunkHash := types.ChunkHash(fmt.Sprintf("file%d_chunk%d", i, j))
-			chunk := &Chunk{
+			chunk := &database.Chunk{
 				ChunkHash: chunkHash,
 				Size:      1024,
 			}
+
 			err := chunkRepo.Create(ctx, nil, chunk)
 			if err != nil {
 				t.Fatalf("failed to create chunk %s: %v", chunkHash, err)
@@ -165,12 +196,13 @@ func TestFileChunkRepositoryMultipleFiles(t *testing.T) {
 
 	// Create chunks for multiple files
 	for i, file := range files {
-		for j := 0; j < 2; j++ {
-			fc := &FileChunk{
+		for j := range 2 {
+			fc := &database.FileChunk{
 				FileID:    file.ID,
 				Idx:       j,
 				ChunkHash: types.ChunkHash(fmt.Sprintf("file%d_chunk%d", i, j)),
 			}
+
 			err := repo.Create(ctx, nil, fc)
 			if err != nil {
 				t.Fatalf("failed to create file chunk: %v", err)
@@ -184,6 +216,7 @@ func TestFileChunkRepositoryMultipleFiles(t *testing.T) {
 		if err != nil {
 			t.Fatalf("failed to get chunks for file %d: %v", i, err)
 		}
+
 		if len(chunks) != 2 {
 			t.Errorf("expected 2 chunks for file %d, got %d", i, len(chunks))
 		}

internal/database/files.go

@@ -3,21 +3,29 @@ package database
 import (
 	"context"
 	"database/sql"
+	"errors"
 	"fmt"
+	"strings"
 	"time"
 
 	"sneak.berlin/go/vaultik/internal/log"
 	"sneak.berlin/go/vaultik/internal/types"
 )
 
+// FileRepository provides access to the files table, which stores file
+// metadata (path, times, permissions, ownership, symlink targets).
 type FileRepository struct {
 	db *DB
 }
 
+// NewFileRepository creates a FileRepository backed by db.
 func NewFileRepository(db *DB) *FileRepository {
 	return &FileRepository{db: db}
 }
 
+// Create inserts or updates a file row (upsert on path), using tx when
+// non-nil. The file's ID is generated when zero and updated from the
+// database's RETURNING clause.
 func (r *FileRepository) Create(ctx context.Context, tx *sql.Tx, file *File) error {
 	// Generate UUID if not provided
 	if file.ID.IsZero() {
@@ -38,13 +46,25 @@ func (r *FileRepository) Create(ctx context.Context, tx *sql.Tx, file *File) err
 		RETURNING id
 	`
 
-	var idStr string
-	var err error
+	var (
+		idStr string
+		err   error
+	)
+
 	if tx != nil {
-		LogSQL("Execute", query, file.ID.String(), file.Path.String(), file.SourcePath.String(), file.MTime.Unix(), file.Size, file.Mode, file.UID, file.GID, file.LinkTarget.String())
-		err = tx.QueryRowContext(ctx, query, file.ID.String(), file.Path.String(), file.SourcePath.String(), file.MTime.Unix(), file.Size, file.Mode, file.UID, file.GID, file.LinkTarget.String()).Scan(&idStr)
+		LogSQL("Execute", query,
+			file.ID.String(), file.Path.String(), file.SourcePath.String(),
+			file.MTime.Unix(), file.Size, file.Mode, file.UID, file.GID,
+			file.LinkTarget.String())
+		err = tx.QueryRowContext(ctx, query,
+			file.ID.String(), file.Path.String(), file.SourcePath.String(),
+			file.MTime.Unix(), file.Size, file.Mode, file.UID, file.GID,
+			file.LinkTarget.String()).Scan(&idStr)
 	} else {
-		err = r.db.QueryRowWithLog(ctx, query, file.ID.String(), file.Path.String(), file.SourcePath.String(), file.MTime.Unix(), file.Size, file.Mode, file.UID, file.GID, file.LinkTarget.String()).Scan(&idStr)
+		err = r.db.QueryRowWithLog(ctx, query,
+			file.ID.String(), file.Path.String(), file.SourcePath.String(),
+			file.MTime.Unix(), file.Size, file.Mode, file.UID, file.GID,
+			file.LinkTarget.String()).Scan(&idStr)
 	}
 
 	if err != nil {
@@ -60,6 +80,8 @@ func (r *FileRepository) Create(ctx context.Context, tx *sql.Tx, file *File) err
 	return nil
 }
 
+// GetByPath returns the file at the given path, or nil if the path is not
+// in the index.
 func (r *FileRepository) GetByPath(ctx context.Context, path string) (*File, error) {
 	query := `
 		SELECT id, path, source_path, mtime, size, mode, uid, gid, link_target
@@ -68,9 +90,10 @@ func (r *FileRepository) GetByPath(ctx context.Context, path string) (*File, err
 	`
 
 	file, err := r.scanFile(r.db.conn.QueryRowContext(ctx, query, path))
-	if err == sql.ErrNoRows {
-		return nil, nil
+	if errors.Is(err, sql.ErrNoRows) {
+		return nil, nil //nolint:nilnil // nil,nil signals not-found; callers check nil
 	}
+
 	if err != nil {
 		return nil, fmt.Errorf("querying file: %w", err)
 	}
@@ -87,9 +110,10 @@ func (r *FileRepository) GetByID(ctx context.Context, id types.FileID) (*File, e
 	`
 
 	file, err := r.scanFile(r.db.conn.QueryRowContext(ctx, query, id.String()))
-	if err == sql.ErrNoRows {
-		return nil, nil
+	if errors.Is(err, sql.ErrNoRows) {
+		return nil, nil //nolint:nilnil // nil,nil signals not-found; callers check nil
 	}
+
 	if err != nil {
 		return nil, fmt.Errorf("querying file: %w", err)
 	}
@@ -97,7 +121,11 @@ func (r *FileRepository) GetByID(ctx context.Context, id types.FileID) (*File, e
 	return file, nil
 }
 
-func (r *FileRepository) GetByPathTx(ctx context.Context, tx *sql.Tx, path string) (*File, error) {
+// GetByPathTx returns the file at the given path within a transaction, or
+// nil if the path is not in the index.
+func (r *FileRepository) GetByPathTx(
+	ctx context.Context, tx *sql.Tx, path string,
+) (*File, error) {
 	query := `
 		SELECT id, path, source_path, mtime, size, mode, uid, gid, link_target
 		FROM files
@@ -108,9 +136,10 @@ func (r *FileRepository) GetByPathTx(ctx context.Context, tx *sql.Tx, path strin
 	file, err := r.scanFile(tx.QueryRowContext(ctx, query, path))
 	LogSQL("GetByPathTx Scan complete", query, path)
 
-	if err == sql.ErrNoRows {
-		return nil, nil
+	if errors.Is(err, sql.ErrNoRows) {
+		return nil, nil //nolint:nilnil // nil,nil signals not-found; callers check nil
 	}
+
 	if err != nil {
 		return nil, fmt.Errorf("querying file: %w", err)
 	}
@@ -118,79 +147,16 @@ func (r *FileRepository) GetByPathTx(ctx context.Context, tx *sql.Tx, path strin
 	return file, nil
 }
 
-// scanFile is a helper that scans a single file row
-func (r *FileRepository) scanFile(row *sql.Row) (*File, error) {
-	var file File
-	var idStr, pathStr, sourcePathStr string
-	var mtimeUnix int64
-	var linkTarget sql.NullString
-
-	err := row.Scan(
-		&idStr,
-		&pathStr,
-		&sourcePathStr,
-		&mtimeUnix,
-		&file.Size,
-		&file.Mode,
-		&file.UID,
-		&file.GID,
-		&linkTarget,
-	)
-	if err != nil {
-		return nil, err
-	}
-
-	file.ID, err = types.ParseFileID(idStr)
-	if err != nil {
-		return nil, fmt.Errorf("parsing file ID: %w", err)
-	}
-	file.Path = types.FilePath(pathStr)
-	file.SourcePath = types.SourcePath(sourcePathStr)
-	file.MTime = time.Unix(mtimeUnix, 0).UTC()
-	if linkTarget.Valid {
-		file.LinkTarget = types.FilePath(linkTarget.String)
-	}
-
-	return &file, nil
+// fileRowScanner abstracts *sql.Row and *sql.Rows for scanning a file row.
+type fileRowScanner interface {
+	Scan(dest ...any) error
 }
 
-// scanFileRows is a helper that scans a file row from rows iterator
-func (r *FileRepository) scanFileRows(rows *sql.Rows) (*File, error) {
-	var file File
-	var idStr, pathStr, sourcePathStr string
-	var mtimeUnix int64
-	var linkTarget sql.NullString
-
-	err := rows.Scan(
-		&idStr,
-		&pathStr,
-		&sourcePathStr,
-		&mtimeUnix,
-		&file.Size,
-		&file.Mode,
-		&file.UID,
-		&file.GID,
-		&linkTarget,
-	)
-	if err != nil {
-		return nil, err
-	}
-
-	file.ID, err = types.ParseFileID(idStr)
-	if err != nil {
-		return nil, fmt.Errorf("parsing file ID: %w", err)
-	}
-	file.Path = types.FilePath(pathStr)
-	file.SourcePath = types.SourcePath(sourcePathStr)
-	file.MTime = time.Unix(mtimeUnix, 0).UTC()
-	if linkTarget.Valid {
-		file.LinkTarget = types.FilePath(linkTarget.String)
-	}
-
-	return &file, nil
-}
-
-func (r *FileRepository) ListModifiedSince(ctx context.Context, since time.Time) ([]*File, error) {
+// ListModifiedSince returns all files whose recorded mtime is at or after
+// since, ordered by path.
+func (r *FileRepository) ListModifiedSince(
+	ctx context.Context, since time.Time,
+) ([]*File, error) {
 	query := `
 		SELECT id, path, source_path, mtime, size, mode, uid, gid, link_target
 		FROM files
@@ -205,17 +171,20 @@ func (r *FileRepository) ListModifiedSince(ctx context.Context, since time.Time)
 	defer CloseRows(rows)
 
 	var files []*File
+
 	for rows.Next() {
 		file, err := r.scanFileRows(rows)
 		if err != nil {
 			return nil, fmt.Errorf("scanning file: %w", err)
 		}
+
 		files = append(files, file)
 	}
 
 	return files, rows.Err()
 }
 
+// Delete removes the file row at the given path, using tx when non-nil.
 func (r *FileRepository) Delete(ctx context.Context, tx *sql.Tx, path string) error {
 	query := `DELETE FROM files WHERE path = ?`
 
@@ -234,7 +203,9 @@ func (r *FileRepository) Delete(ctx context.Context, tx *sql.Tx, path string) er
 }
 
 // DeleteByID deletes a file by its UUID
-func (r *FileRepository) DeleteByID(ctx context.Context, tx *sql.Tx, id types.FileID) error {
+func (r *FileRepository) DeleteByID(
+	ctx context.Context, tx *sql.Tx, id types.FileID,
+) error {
 	query := `DELETE FROM files WHERE id = ?`
 
 	var err error
@@ -251,7 +222,11 @@ func (r *FileRepository) DeleteByID(ctx context.Context, tx *sql.Tx, id types.Fi
 	return nil
 }
 
-func (r *FileRepository) ListByPrefix(ctx context.Context, prefix string) ([]*File, error) {
+// ListByPrefix returns all files whose path starts with prefix, ordered by
+// path.
+func (r *FileRepository) ListByPrefix(
+	ctx context.Context, prefix string,
+) ([]*File, error) {
 	query := `
 		SELECT id, path, source_path, mtime, size, mode, uid, gid, link_target
 		FROM files
@@ -266,11 +241,13 @@ func (r *FileRepository) ListByPrefix(ctx context.Context, prefix string) ([]*Fi
 	defer CloseRows(rows)
 
 	var files []*File
+
 	for rows.Next() {
 		file, err := r.scanFileRows(rows)
 		if err != nil {
 			return nil, fmt.Errorf("scanning file: %w", err)
 		}
+
 		files = append(files, file)
 	}
 
@@ -292,11 +269,13 @@ func (r *FileRepository) ListAll(ctx context.Context) ([]*File, error) {
 	defer CloseRows(rows)
 
 	var files []*File
+
 	for rows.Next() {
 		file, err := r.scanFileRows(rows)
 		if err != nil {
 			return nil, fmt.Errorf("scanning file: %w", err)
 		}
+
 		files = append(files, file)
 	}
 
@@ -305,30 +284,47 @@ func (r *FileRepository) ListAll(ctx context.Context) ([]*File, error) {
 
 // CreateBatch inserts or updates multiple files in a single statement for efficiency.
 // File IDs must be pre-generated before calling this method.
-func (r *FileRepository) CreateBatch(ctx context.Context, tx *sql.Tx, files []*File) error {
+func (r *FileRepository) CreateBatch(
+	ctx context.Context, tx *sql.Tx, files []*File,
+) error {
 	if len(files) == 0 {
 		return nil
 	}
 
-	// Each File has 9 values, so batch at 100 to be safe with SQLite's variable limit
+	// Each files row binds this many SQL variables.
+	const fileCols = 9
+
+	// Batch at 100 rows to be safe with SQLite's variable limit.
 	const batchSize = 100
 
 	for i := 0; i < len(files); i += batchSize {
-		end := i + batchSize
-		if end > len(files) {
-			end = len(files)
-		}
+		end := min(i+batchSize, len(files))
+
 		batch := files[i:end]
 
-		query := `INSERT INTO files (id, path, source_path, mtime, size, mode, uid, gid, link_target) VALUES `
-		args := make([]interface{}, 0, len(batch)*9)
+		query := `INSERT INTO files
+			(id, path, source_path, mtime, size, mode, uid, gid, link_target)
+			VALUES `
+
+		args := make([]any, 0, len(batch)*fileCols)
+
+		var querySb325 strings.Builder
+
 		for j, f := range batch {
 			if j > 0 {
-				query += ", "
+				querySb325.WriteString(", ")
 			}
-			query += "(?, ?, ?, ?, ?, ?, ?, ?, ?)"
-			args = append(args, f.ID.String(), f.Path.String(), f.SourcePath.String(), f.MTime.Unix(), f.Size, f.Mode, f.UID, f.GID, f.LinkTarget.String())
+
+			querySb325.WriteString("(?, ?, ?, ?, ?, ?, ?, ?, ?)")
+
+			args = append(args,
+				f.ID.String(), f.Path.String(), f.SourcePath.String(),
+				f.MTime.Unix(), f.Size, f.Mode, f.UID, f.GID,
+				f.LinkTarget.String())
 		}
+
+		query += querySb325.String() //nolint:gosec // G202: appends "?" placeholders only
+
 		query += ` ON CONFLICT(path) DO UPDATE SET
 			source_path = excluded.source_path,
 			mtime = excluded.mtime,
@@ -344,6 +340,7 @@ func (r *FileRepository) CreateBatch(ctx context.Context, tx *sql.Tx, files []*F
 		} else {
 			_, err = r.db.ExecWithLog(ctx, query, args...)
 		}
+
 		if err != nil {
 			return fmt.Errorf("batch inserting files: %w", err)
 		}
@@ -374,3 +371,53 @@ func (r *FileRepository) DeleteOrphaned(ctx context.Context) error {
 
 	return nil
 }
+
+// scanFile is a helper that scans a single file row
+func (r *FileRepository) scanFile(row *sql.Row) (*File, error) {
+	return r.scanFileFrom(row)
+}
+
+// scanFileRows is a helper that scans a file row from rows iterator
+func (r *FileRepository) scanFileRows(rows *sql.Rows) (*File, error) {
+	return r.scanFileFrom(rows)
+}
+
+// scanFileFrom scans one file row from any row scanner.
+func (r *FileRepository) scanFileFrom(row fileRowScanner) (*File, error) {
+	var (
+		file                          File
+		idStr, pathStr, sourcePathStr string
+		mtimeUnix                     int64
+		linkTarget                    sql.NullString
+	)
+
+	err := row.Scan(
+		&idStr,
+		&pathStr,
+		&sourcePathStr,
+		&mtimeUnix,
+		&file.Size,
+		&file.Mode,
+		&file.UID,
+		&file.GID,
+		&linkTarget,
+	)
+	if err != nil {
+		return nil, err
+	}
+
+	file.ID, err = types.ParseFileID(idStr)
+	if err != nil {
+		return nil, fmt.Errorf("parsing file ID: %w", err)
+	}
+
+	file.Path = types.FilePath(pathStr)
+	file.SourcePath = types.SourcePath(sourcePathStr)
+
+	file.MTime = time.Unix(mtimeUnix, 0).UTC()
+	if linkTarget.Valid {
+		file.LinkTarget = types.FilePath(linkTarget.String)
+	}
+
+	return &file, nil
+}

internal/database/files_test.go

@@ -1,43 +1,32 @@
-package database
+package database_test
 
 import (
 	"context"
 	"database/sql"
-	"fmt"
+	"errors"
 	"os"
-	"path/filepath"
 	"testing"
 	"time"
+
+	"sneak.berlin/go/vaultik/internal/database"
 )
 
-func setupTestDB(t *testing.T) (*DB, func()) {
-	ctx := context.Background()
-	dbPath := filepath.Join(t.TempDir(), "test.db")
-
-	db, err := New(ctx, dbPath)
-	if err != nil {
-		t.Fatalf("failed to create database: %v", err)
-	}
-
-	cleanup := func() {
-		if err := db.Close(); err != nil {
-			t.Errorf("failed to close database: %v", err)
-		}
-	}
-
-	return db, cleanup
-}
+// errTestRollback is the sentinel returned from transaction bodies to
+// force a rollback in tests.
+var errTestRollback = errors.New("test rollback")
 
 func TestFileRepository(t *testing.T) {
+	t.Parallel()
+
 	db, cleanup := setupTestDB(t)
 	defer cleanup()
 
 	ctx := context.Background()
-	repo := NewFileRepository(db)
+	repo := database.NewFileRepository(db)
 
 	// Test Create
-	file := &File{
-		Path:       "/test/file.txt",
+	file := &database.File{
+		Path:       testFileTxt,
 		MTime:      time.Now().Truncate(time.Second),
 		Size:       1024,
 		Mode:       0644,
@@ -56,18 +45,23 @@ func TestFileRepository(t *testing.T) {
 	if err != nil {
 		t.Fatalf("failed to get file: %v", err)
 	}
+
 	if retrieved == nil {
 		t.Fatal("expected file, got nil")
 	}
+
 	if retrieved.Path != file.Path {
 		t.Errorf("path mismatch: got %s, want %s", retrieved.Path, file.Path)
 	}
+
 	if !retrieved.MTime.Equal(file.MTime) {
 		t.Errorf("mtime mismatch: got %v, want %v", retrieved.MTime, file.MTime)
 	}
+
 	if retrieved.Size != file.Size {
 		t.Errorf("size mismatch: got %d, want %d", retrieved.Size, file.Size)
 	}
+
 	if retrieved.Mode != file.Mode {
 		t.Errorf("mode mismatch: got %o, want %o", retrieved.Mode, file.Mode)
 	}
@@ -75,6 +69,7 @@ func TestFileRepository(t *testing.T) {
 	// Test Update (upsert)
 	file.Size = 2048
 	file.MTime = time.Now().Truncate(time.Second)
+
 	err = repo.Create(ctx, nil, file)
 	if err != nil {
 		t.Fatalf("failed to update file: %v", err)
@@ -84,15 +79,41 @@ func TestFileRepository(t *testing.T) {
 	if err != nil {
 		t.Fatalf("failed to get updated file: %v", err)
 	}
+
 	if retrieved.Size != 2048 {
 		t.Errorf("size not updated: got %d, want %d", retrieved.Size, 2048)
 	}
+}
+
+func TestFileRepositoryListDelete(t *testing.T) {
+	t.Parallel()
+
+	db, cleanup := setupTestDB(t)
+	defer cleanup()
+
+	ctx := context.Background()
+	repo := database.NewFileRepository(db)
+
+	file := &database.File{
+		Path:  testFileTxt,
+		MTime: time.Now().Truncate(time.Second),
+		Size:  1024,
+		Mode:  0644,
+		UID:   1000,
+		GID:   1000,
+	}
+
+	err := repo.Create(ctx, nil, file)
+	if err != nil {
+		t.Fatalf("failed to create file: %v", err)
+	}
 
 	// Test ListModifiedSince
 	files, err := repo.ListModifiedSince(ctx, time.Now().Add(-1*time.Hour))
 	if err != nil {
 		t.Fatalf("failed to list files: %v", err)
 	}
+
 	if len(files) != 1 {
 		t.Errorf("expected 1 file, got %d", len(files))
 	}
@@ -103,24 +124,27 @@ func TestFileRepository(t *testing.T) {
 		t.Fatalf("failed to delete file: %v", err)
 	}
 
-	retrieved, err = repo.GetByPath(ctx, file.Path.String())
+	retrieved, err := repo.GetByPath(ctx, file.Path.String())
 	if err != nil {
 		t.Fatalf("error getting deleted file: %v", err)
 	}
+
 	if retrieved != nil {
 		t.Error("expected nil for deleted file")
 	}
 }
 
 func TestFileRepositorySymlink(t *testing.T) {
+	t.Parallel()
+
 	db, cleanup := setupTestDB(t)
 	defer cleanup()
 
 	ctx := context.Background()
-	repo := NewFileRepository(db)
+	repo := database.NewFileRepository(db)
 
 	// Test symlink
-	symlink := &File{
+	symlink := &database.File{
 		Path:       "/test/link",
 		MTime:      time.Now().Truncate(time.Second),
 		Size:       0,
@@ -139,25 +163,30 @@ func TestFileRepositorySymlink(t *testing.T) {
 	if err != nil {
 		t.Fatalf("failed to get symlink: %v", err)
 	}
+
 	if !retrieved.IsSymlink() {
 		t.Error("expected IsSymlink() to be true")
 	}
+
 	if retrieved.LinkTarget != symlink.LinkTarget {
-		t.Errorf("link target mismatch: got %s, want %s", retrieved.LinkTarget, symlink.LinkTarget)
+		t.Errorf("link target mismatch: got %s, want %s",
+			retrieved.LinkTarget, symlink.LinkTarget)
 	}
 }
 
 func TestFileRepositoryTransaction(t *testing.T) {
+	t.Parallel()
+
 	db, cleanup := setupTestDB(t)
 	defer cleanup()
 
 	ctx := context.Background()
-	repos := NewRepositories(db)
+	repos := database.NewRepositories(db)
 
 	// Test transaction rollback
 	err := repos.WithTx(ctx, func(ctx context.Context, tx *sql.Tx) error {
-		file := &File{
-			Path:  "/test/tx_file.txt",
+		file := &database.File{
+			Path:  testTxFile,
 			MTime: time.Now().Truncate(time.Second),
 			Size:  1024,
 			Mode:  0644,
@@ -165,23 +194,24 @@ func TestFileRepositoryTransaction(t *testing.T) {
 			GID:   1000,
 		}
 
-		if err := repos.Files.Create(ctx, tx, file); err != nil {
+		err := repos.Files.Create(ctx, tx, file)
+		if err != nil {
 			return err
 		}
 
 		// Return error to trigger rollback
-		return fmt.Errorf("test rollback")
+		return errTestRollback
 	})
-
-	if err == nil || err.Error() != "test rollback" {
+	if !errors.Is(err, errTestRollback) {
 		t.Fatalf("expected rollback error, got: %v", err)
 	}
 
 	// Verify file was not created
-	retrieved, err := repos.Files.GetByPath(ctx, "/test/tx_file.txt")
+	retrieved, err := repos.Files.GetByPath(ctx, testTxFile)
 	if err != nil {
 		t.Fatalf("error checking for file: %v", err)
 	}
+
 	if retrieved != nil {
 		t.Error("file should not exist after rollback")
 	}

internal/database/helpers_internal_test.go

@@ -0,0 +1,81 @@
+package database
+
+import (
+	"context"
+	"path/filepath"
+	"testing"
+
+	"sneak.berlin/go/vaultik/internal/types"
+)
+
+// Common fixture values shared by the internal repository tests.
+const (
+	internalTestHost       = "test-host"
+	internalTestSnapshotID = "test-snapshot"
+	internalTestFilePath   = "/test.txt"
+	internalTestFile1      = "/file1.txt"
+	internalTestFile2      = "/file2.txt"
+
+	// countFilesQuery counts the rows of the files table.
+	countFilesQuery = "SELECT COUNT(*) FROM files"
+)
+
+// mustCreateFileRow inserts the file row, failing the test on error.
+func mustCreateFileRow(t *testing.T, repos *Repositories, file *File) {
+	t.Helper()
+
+	err := repos.Files.Create(context.Background(), nil, file)
+	if err != nil {
+		t.Fatalf("failed to create file %s: %v", file.Path, err)
+	}
+}
+
+// mustAddFileToSnapshot associates a file with a snapshot, failing the
+// test on error.
+func mustAddFileToSnapshot(
+	t *testing.T, repos *Repositories, snapshotID string, fileID types.FileID,
+) {
+	t.Helper()
+
+	err := repos.Snapshots.AddFileByID(context.Background(), nil, snapshotID, fileID)
+	if err != nil {
+		t.Fatal(err)
+	}
+}
+
+// setupTestDB creates an on-disk test database in a per-test temp
+// directory and returns it along with a cleanup func that closes it.
+func setupTestDB(t *testing.T) (*DB, func()) {
+	t.Helper()
+
+	ctx := context.Background()
+	dbPath := filepath.Join(t.TempDir(), "test.db")
+
+	db, err := New(ctx, dbPath)
+	if err != nil {
+		t.Fatalf("failed to create database: %v", err)
+	}
+
+	cleanup := func() {
+		err := db.Close()
+		if err != nil {
+			t.Errorf("failed to close database: %v", err)
+		}
+	}
+
+	return db, cleanup
+}
+
+// countRow runs a single-integer COUNT-style query and returns the value.
+func countRow(t *testing.T, db *DB, query string, args ...any) int {
+	t.Helper()
+
+	var count int
+
+	err := db.conn.QueryRowContext(context.Background(), query, args...).Scan(&count)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	return count
+}

internal/database/helpers_test.go

@@ -0,0 +1,52 @@
+package database_test
+
+import (
+	"context"
+	"path/filepath"
+	"testing"
+
+	"sneak.berlin/go/vaultik/internal/database"
+)
+
+// Common fixture values shared by the repository tests.
+const (
+	testFilePath1 = "/file1.txt"
+	testFilePath2 = "/file2.txt"
+	testFileTxt   = "/test/file.txt"
+	testTxFile    = "/test/tx_file.txt"
+	testHostname  = "test-host"
+	testVersion   = "1.0.0"
+)
+
+// mustCreateFile inserts the given file row, failing the test on error.
+func mustCreateFile(t *testing.T, repo *database.FileRepository, file *database.File) {
+	t.Helper()
+
+	err := repo.Create(context.Background(), nil, file)
+	if err != nil {
+		t.Fatalf("failed to create file %s: %v", file.Path, err)
+	}
+}
+
+// setupTestDB creates an on-disk test database in a per-test temp
+// directory and returns it along with a cleanup func that closes it.
+func setupTestDB(t *testing.T) (*database.DB, func()) {
+	t.Helper()
+
+	ctx := context.Background()
+	dbPath := filepath.Join(t.TempDir(), "test.db")
+
+	db, err := database.New(ctx, dbPath)
+	if err != nil {
+		t.Fatalf("failed to create database: %v", err)
+	}
+
+	cleanup := func() {
+		err := db.Close()
+		if err != nil {
+			t.Errorf("failed to close database: %v", err)
+		}
+	}
+
+	return db, cleanup
+}

internal/database/local_meta.go

@@ -18,6 +18,7 @@ type LocalMetaRepository struct {
 	db *DB
 }
 
+// NewLocalMetaRepository creates a LocalMetaRepository backed by db.
 func NewLocalMetaRepository(db *DB) *LocalMetaRepository {
 	return &LocalMetaRepository{db: db}
 }
@@ -27,15 +28,18 @@ func NewLocalMetaRepository(db *DB) *LocalMetaRepository {
 // "unset" (bind on first use) from "set to something" (compare).
 func (r *LocalMetaRepository) Get(ctx context.Context, key string) (string, error) {
 	var value string
+
 	err := r.db.conn.QueryRowContext(ctx,
 		"SELECT value FROM local_meta WHERE key = ?", key,
 	).Scan(&value)
 	if errors.Is(err, sql.ErrNoRows) {
 		return "", nil
 	}
+
 	if err != nil {
 		return "", fmt.Errorf("reading local_meta %q: %w", key, err)
 	}
+
 	return value, nil
 }
 
@@ -49,5 +53,6 @@ func (r *LocalMetaRepository) Set(ctx context.Context, key, value string) error
 	if err != nil {
 		return fmt.Errorf("writing local_meta %q: %w", key, err)
 	}
+
 	return nil
 }

internal/database/local_meta_test.go

@@ -9,26 +9,33 @@ import (
 )
 
 func TestLocalMetaEmptyOnFresh(t *testing.T) {
+	t.Parallel()
+
 	db, err := database.NewTestDB()
 	require.NoError(t, err)
+
 	defer func() { _ = db.Close() }()
 
 	repos := database.NewRepositories(db)
 
 	got, err := repos.LocalMeta.Get(context.Background(), database.LocalMetaKeyStorageURL)
 	require.NoError(t, err)
-	require.Equal(t, "", got, "fresh DB must return empty for unset keys, not error")
+	require.Empty(t, got, "fresh DB must return empty for unset keys, not error")
 }
 
 func TestLocalMetaSetGetRoundTrip(t *testing.T) {
+	t.Parallel()
+
 	db, err := database.NewTestDB()
 	require.NoError(t, err)
+
 	defer func() { _ = db.Close() }()
 
 	repos := database.NewRepositories(db)
 	ctx := context.Background()
 
-	require.NoError(t, repos.LocalMeta.Set(ctx, database.LocalMetaKeyStorageURL, "file:///mnt/backups"))
+	require.NoError(t, repos.LocalMeta.Set(
+		ctx, database.LocalMetaKeyStorageURL, "file:///mnt/backups"))
 
 	got, err := repos.LocalMeta.Get(ctx, database.LocalMetaKeyStorageURL)
 	require.NoError(t, err)
@@ -36,15 +43,20 @@ func TestLocalMetaSetGetRoundTrip(t *testing.T) {
 }
 
 func TestLocalMetaSetOverwrites(t *testing.T) {
+	t.Parallel()
+
 	db, err := database.NewTestDB()
 	require.NoError(t, err)
+
 	defer func() { _ = db.Close() }()
 
 	repos := database.NewRepositories(db)
 	ctx := context.Background()
 
-	require.NoError(t, repos.LocalMeta.Set(ctx, database.LocalMetaKeyStorageURL, "s3://old"))
-	require.NoError(t, repos.LocalMeta.Set(ctx, database.LocalMetaKeyStorageURL, "s3://new"))
+	require.NoError(t, repos.LocalMeta.Set(
+		ctx, database.LocalMetaKeyStorageURL, "s3://old"))
+	require.NoError(t, repos.LocalMeta.Set(
+		ctx, database.LocalMetaKeyStorageURL, "s3://new"))
 
 	got, err := repos.LocalMeta.Get(ctx, database.LocalMetaKeyStorageURL)
 	require.NoError(t, err)

internal/database/models.go

@@ -1,5 +1,3 @@
-// Package database provides data models and repository interfaces for the Vaultik backup system.
-// It includes types for files, chunks, blobs, snapshots, and their relationships.
 package database
 
 import (
@@ -15,7 +13,10 @@ import (
 type File struct {
 	ID   types.FileID   // UUID primary key
 	Path types.FilePath // Absolute path of the file
-	SourcePath types.SourcePath // The source directory this file came from (for restore path stripping)
+
+	// SourcePath is the source directory this file came from (used for
+	// restore path stripping).
+	SourcePath types.SourcePath
 	MTime      time.Time
 	Size       int64
 	Mode       uint32
@@ -56,7 +57,10 @@ type Chunk struct {
 // -> encrypted with age -> hashed -> uploaded to S3 with the hash as filename.
 type Blob struct {
 	ID types.BlobID // UUID assigned when blob creation starts
-	Hash             types.BlobHash // SHA256 of final compressed+encrypted content (empty until finalized)
+
+	// Hash is the SHA256 of the final compressed+encrypted content
+	// (empty until finalized).
+	Hash             types.BlobHash
 	CreatedTS        time.Time  // When blob creation started
 	FinishedTS       *time.Time // When blob was finalized (nil if still packing)
 	UncompressedSize int64      // Total size of raw chunks before compression
@@ -75,9 +79,10 @@ type BlobChunk struct {
 	Length    int64
 }
 
-// ChunkFile represents the reverse mapping showing which files contain a specific chunk.
-// This is used during deduplication to identify all files that share a chunk,
-// which is important for garbage collection and integrity verification.
+// ChunkFile represents the reverse mapping showing which files contain a
+// specific chunk. This is used during deduplication to identify all files
+// that share a chunk, which is important for garbage collection and
+// integrity verification.
 type ChunkFile struct {
 	ChunkHash  types.ChunkHash
 	FileID     types.FileID
@@ -97,7 +102,10 @@ type Snapshot struct {
 	ChunkCount         int64
 	BlobCount          int64
 	TotalSize          int64 // Total size of all referenced files
-	BlobSize             int64   // Total size of all referenced blobs (compressed and encrypted)
+
+	// BlobSize is the total size of all referenced blobs (compressed and
+	// encrypted).
+	BlobSize             int64
 	BlobUncompressedSize int64   // Total uncompressed size of all referenced blobs
 	CompressionRatio     float64 // Compression ratio (BlobSize / BlobUncompressedSize)
 	CompressionLevel     int     // Compression level used for this snapshot

internal/database/module.go

@@ -11,7 +11,13 @@ import (
 	"sneak.berlin/go/vaultik/internal/log"
 )
 
+// indexDirPerm restricts the local index directory to the owning user;
+// the index describes the backed-up file tree and must stay private.
+const indexDirPerm = 0o700
+
 // Module provides database dependencies
+//
+//nolint:gochecknoglobals // fx module definitions are package globals by convention
 var Module = fx.Module("database",
 	fx.Provide(
 		provideDatabase,
@@ -22,7 +28,9 @@ var Module = fx.Module("database",
 func provideDatabase(lc fx.Lifecycle, cfg *config.Config) (*DB, error) {
 	// Ensure the index directory exists
 	indexDir := filepath.Dir(cfg.IndexPath)
-	if err := os.MkdirAll(indexDir, 0700); err != nil {
+
+	err := os.MkdirAll(indexDir, indexDirPerm)
+	if err != nil {
 		return nil, fmt.Errorf("creating index directory: %w", err)
 	}
 
@@ -32,13 +40,18 @@ func provideDatabase(lc fx.Lifecycle, cfg *config.Config) (*DB, error) {
 	}
 
 	lc.Append(fx.Hook{
-		OnStop: func(ctx context.Context) error {
+		OnStop: func(_ context.Context) error {
 			log.Debug("Database module OnStop hook called")
-			if err := db.Close(); err != nil {
+
+			err := db.Close()
+			if err != nil {
 				log.Error("Failed to close database in OnStop hook", "error", err)
+
 				return err
 			}
+
 			log.Debug("Database closed successfully in OnStop hook")
+
 			return nil
 		},
 	})

internal/database/repositories.go

@@ -50,21 +50,26 @@ type TxFunc func(ctx context.Context, tx *sql.Tx) error
 // This method should be used for all write operations to ensure atomicity.
 func (r *Repositories) WithTx(ctx context.Context, fn TxFunc) error {
 	LogSQL("WithTx", "Beginning transaction", "")
+
 	tx, err := r.db.BeginTx(ctx, nil)
 	if err != nil {
 		return fmt.Errorf("beginning transaction: %w", err)
 	}
+
 	LogSQL("WithTx", "Transaction started", "")
 
 	defer func() {
 		if p := recover(); p != nil {
-			if rollbackErr := tx.Rollback(); rollbackErr != nil {
-				Fatal("failed to rollback transaction: %v", rollbackErr)
+			rollbackErr := tx.Rollback()
+			if rollbackErr != nil {
+				Fatalf("failed to rollback transaction: %v", rollbackErr)
 			}
+
 			panic(p)
 		} else if err != nil {
-			if rollbackErr := tx.Rollback(); rollbackErr != nil {
-				Fatal("failed to rollback transaction: %v", rollbackErr)
+			rollbackErr := tx.Rollback()
+			if rollbackErr != nil {
+				Fatalf("failed to rollback transaction: %v", rollbackErr)
 			}
 		}
 	}()
@@ -90,6 +95,7 @@ func (r *Repositories) WithReadTx(ctx context.Context, fn TxFunc) error {
 	opts := &sql.TxOptions{
 		ReadOnly: true,
 	}
+
 	tx, err := r.db.BeginTx(ctx, opts)
 	if err != nil {
 		return fmt.Errorf("beginning read transaction: %w", err)
@@ -97,13 +103,16 @@ func (r *Repositories) WithReadTx(ctx context.Context, fn TxFunc) error {
 
 	defer func() {
 		if p := recover(); p != nil {
-			if rollbackErr := tx.Rollback(); rollbackErr != nil {
-				Fatal("failed to rollback transaction: %v", rollbackErr)
+			rollbackErr := tx.Rollback()
+			if rollbackErr != nil {
+				Fatalf("failed to rollback transaction: %v", rollbackErr)
 			}
+
 			panic(p)
 		} else if err != nil {
-			if rollbackErr := tx.Rollback(); rollbackErr != nil {
-				Fatal("failed to rollback transaction: %v", rollbackErr)
+			rollbackErr := tx.Rollback()
+			if rollbackErr != nil {
+				Fatalf("failed to rollback transaction: %v", rollbackErr)
 			}
 		}
 	}()

internal/database/repositories_test.go

@@ -1,124 +1,162 @@
-package database
+package database_test
 
 import (
 	"context"
 	"database/sql"
-	"fmt"
+	"errors"
 	"testing"
 	"time"
 
+	"sneak.berlin/go/vaultik/internal/database"
 	"sneak.berlin/go/vaultik/internal/types"
 )
 
-func TestRepositoriesTransaction(t *testing.T) {
-	db, cleanup := setupTestDB(t)
-	defer cleanup()
+// errIntentionalRollback forces a transaction rollback in tests.
+var errIntentionalRollback = errors.New("intentional rollback")
 
-	ctx := context.Background()
-	repos := NewRepositories(db)
-
-	// Test successful transaction with multiple operations
-	err := repos.WithTx(ctx, func(ctx context.Context, tx *sql.Tx) error {
-		// Create a file
-		file := &File{
-			Path:  "/test/tx_file.txt",
+// createTxTestData returns a transaction body that creates a file with
+// two chunks packed into one blob.
+func createTxTestData(
+	repos *database.Repositories,
+) func(context.Context, *sql.Tx) error {
+	return func(ctx context.Context, tx *sql.Tx) error {
+		file := &database.File{
+			Path:  testTxFile,
 			MTime: time.Now().Truncate(time.Second),
 			Size:  1024,
 			Mode:  0644,
 			UID:   1000,
 			GID:   1000,
 		}
-		if err := repos.Files.Create(ctx, tx, file); err != nil {
+
+		err := repos.Files.Create(ctx, tx, file)
+		if err != nil {
 			return err
 		}
 
+		err = createTxFileChunks(ctx, tx, repos, file.ID)
+		if err != nil {
+			return err
+		}
+
+		return createTxBlob(ctx, tx, repos)
+	}
+}
+
+// createTxFileChunks creates the two test chunks and maps them to the file.
+func createTxFileChunks(
+	ctx context.Context, tx *sql.Tx,
+	repos *database.Repositories, fileID types.FileID,
+) error {
 	// Create chunks
-		chunk1 := &Chunk{
+	chunk1 := &database.Chunk{
 		ChunkHash: types.ChunkHash("tx_chunk1"),
 		Size:      512,
 	}
-		if err := repos.Chunks.Create(ctx, tx, chunk1); err != nil {
+
+	err := repos.Chunks.Create(ctx, tx, chunk1)
+	if err != nil {
 		return err
 	}
 
-		chunk2 := &Chunk{
+	chunk2 := &database.Chunk{
 		ChunkHash: types.ChunkHash("tx_chunk2"),
 		Size:      512,
 	}
-		if err := repos.Chunks.Create(ctx, tx, chunk2); err != nil {
+
+	err = repos.Chunks.Create(ctx, tx, chunk2)
+	if err != nil {
 		return err
 	}
 
 	// Map chunks to file
-		fc1 := &FileChunk{
-			FileID:    file.ID,
+	fc1 := &database.FileChunk{
+		FileID:    fileID,
 		Idx:       0,
 		ChunkHash: chunk1.ChunkHash,
 	}
-		if err := repos.FileChunks.Create(ctx, tx, fc1); err != nil {
+
+	err = repos.FileChunks.Create(ctx, tx, fc1)
+	if err != nil {
 		return err
 	}
 
-		fc2 := &FileChunk{
-			FileID:    file.ID,
+	fc2 := &database.FileChunk{
+		FileID:    fileID,
 		Idx:       1,
 		ChunkHash: chunk2.ChunkHash,
 	}
-		if err := repos.FileChunks.Create(ctx, tx, fc2); err != nil {
-			return err
-		}
 
-		// Create blob
-		blob := &Blob{
+	return repos.FileChunks.Create(ctx, tx, fc2)
+}
+
+// createTxBlob creates the test blob and maps both chunks into it.
+func createTxBlob(
+	ctx context.Context, tx *sql.Tx, repos *database.Repositories,
+) error {
+	blob := &database.Blob{
 		ID:        types.NewBlobID(),
 		Hash:      types.BlobHash("tx_blob1"),
 		CreatedTS: time.Now().Truncate(time.Second),
 	}
-		if err := repos.Blobs.Create(ctx, tx, blob); err != nil {
+
+	err := repos.Blobs.Create(ctx, tx, blob)
+	if err != nil {
 		return err
 	}
 
 	// Map chunks to blob
-		bc1 := &BlobChunk{
+	bc1 := &database.BlobChunk{
 		BlobID:    blob.ID,
-			ChunkHash: chunk1.ChunkHash,
+		ChunkHash: types.ChunkHash("tx_chunk1"),
 		Offset:    0,
 		Length:    512,
 	}
-		if err := repos.BlobChunks.Create(ctx, tx, bc1); err != nil {
+
+	err = repos.BlobChunks.Create(ctx, tx, bc1)
+	if err != nil {
 		return err
 	}
 
-		bc2 := &BlobChunk{
+	bc2 := &database.BlobChunk{
 		BlobID:    blob.ID,
-			ChunkHash: chunk2.ChunkHash,
+		ChunkHash: types.ChunkHash("tx_chunk2"),
 		Offset:    512,
 		Length:    512,
 	}
-		if err := repos.BlobChunks.Create(ctx, tx, bc2); err != nil {
-			return err
-		}
 
-		return nil
-	})
+	return repos.BlobChunks.Create(ctx, tx, bc2)
+}
 
+func TestRepositoriesTransaction(t *testing.T) {
+	t.Parallel()
+
+	db, cleanup := setupTestDB(t)
+	defer cleanup()
+
+	ctx := context.Background()
+	repos := database.NewRepositories(db)
+
+	err := repos.WithTx(ctx, createTxTestData(repos))
 	if err != nil {
 		t.Fatalf("transaction failed: %v", err)
 	}
 
 	// Verify all data was committed
-	file, err := repos.Files.GetByPath(ctx, "/test/tx_file.txt")
+	file, err := repos.Files.GetByPath(ctx, testTxFile)
 	if err != nil {
 		t.Fatalf("failed to get file: %v", err)
 	}
+
 	if file == nil {
 		t.Error("expected file after transaction")
 	}
 
-	chunks, err := repos.FileChunks.GetByFile(ctx, "/test/tx_file.txt")
+	chunks, err := repos.FileChunks.GetByFile(ctx, testTxFile)
 	if err != nil {
 		t.Fatalf("failed to get file chunks: %v", err)
 	}
+
 	if len(chunks) != 2 {
 		t.Errorf("expected 2 file chunks, got %d", len(chunks))
 	}
@@ -127,22 +165,25 @@ func TestRepositoriesTransaction(t *testing.T) {
 	if err != nil {
 		t.Fatalf("failed to get blob: %v", err)
 	}
+
 	if blob == nil {
 		t.Error("expected blob after transaction")
 	}
 }
 
 func TestRepositoriesTransactionRollback(t *testing.T) {
+	t.Parallel()
+
 	db, cleanup := setupTestDB(t)
 	defer cleanup()
 
 	ctx := context.Background()
-	repos := NewRepositories(db)
+	repos := database.NewRepositories(db)
 
 	// Test transaction rollback
 	err := repos.WithTx(ctx, func(ctx context.Context, tx *sql.Tx) error {
 		// Create a file
-		file := &File{
+		file := &database.File{
 			Path:  "/test/rollback_file.txt",
 			MTime: time.Now().Truncate(time.Second),
 			Size:  1024,
@@ -150,24 +191,27 @@ func TestRepositoriesTransactionRollback(t *testing.T) {
 			UID:   1000,
 			GID:   1000,
 		}
-		if err := repos.Files.Create(ctx, tx, file); err != nil {
+
+		err := repos.Files.Create(ctx, tx, file)
+		if err != nil {
 			return err
 		}
 
 		// Create a chunk
-		chunk := &Chunk{
+		chunk := &database.Chunk{
 			ChunkHash: types.ChunkHash("rollback_chunk"),
 			Size:      1024,
 		}
-		if err := repos.Chunks.Create(ctx, tx, chunk); err != nil {
+
+		err = repos.Chunks.Create(ctx, tx, chunk)
+		if err != nil {
 			return err
 		}
 
 		// Return error to trigger rollback
-		return fmt.Errorf("intentional rollback")
+		return errIntentionalRollback
 	})
-
-	if err == nil || err.Error() != "intentional rollback" {
+	if !errors.Is(err, errIntentionalRollback) {
 		t.Fatalf("expected rollback error, got: %v", err)
 	}
 
@@ -176,6 +220,7 @@ func TestRepositoriesTransactionRollback(t *testing.T) {
 	if err != nil {
 		t.Fatalf("error checking for file: %v", err)
 	}
+
 	if file != nil {
 		t.Error("file should not exist after rollback")
 	}
@@ -184,20 +229,23 @@ func TestRepositoriesTransactionRollback(t *testing.T) {
 	if err != nil {
 		t.Fatalf("error checking for chunk: %v", err)
 	}
+
 	if chunk != nil {
 		t.Error("chunk should not exist after rollback")
 	}
 }
 
 func TestRepositoriesReadTransaction(t *testing.T) {
+	t.Parallel()
+
 	db, cleanup := setupTestDB(t)
 	defer cleanup()
 
 	ctx := context.Background()
-	repos := NewRepositories(db)
+	repos := database.NewRepositories(db)
 
 	// First, create some data
-	file := &File{
+	file := &database.File{
 		Path:  "/test/read_file.txt",
 		MTime: time.Now().Truncate(time.Second),
 		Size:  1024,
@@ -205,22 +253,25 @@ func TestRepositoriesReadTransaction(t *testing.T) {
 		UID:   1000,
 		GID:   1000,
 	}
+
 	err := repos.Files.Create(ctx, nil, file)
 	if err != nil {
 		t.Fatalf("failed to create file: %v", err)
 	}
 
 	// Test read-only transaction
-	var retrievedFile *File
+	var retrievedFile *database.File
+
 	err = repos.WithReadTx(ctx, func(ctx context.Context, tx *sql.Tx) error {
 		var err error
+
 		retrievedFile, err = repos.Files.GetByPathTx(ctx, tx, "/test/read_file.txt")
 		if err != nil {
 			return err
 		}
 
 		// Try to write in read-only transaction (should fail)
-		_ = repos.Files.Create(ctx, tx, &File{
+		_ = repos.Files.Create(ctx, tx, &database.File{
 			Path:  "/test/should_fail.txt",
 			MTime: time.Now(),
 			Size:  0,
@@ -232,7 +283,6 @@ func TestRepositoriesReadTransaction(t *testing.T) {
 
 		return nil
 	})
-
 	if err != nil {
 		t.Fatalf("read transaction failed: %v", err)
 	}

internal/database/repository_comprehensive_test.go

@@ -1,8 +1,10 @@
+//nolint:testpackage // inspects the unexported database connection
 package database
 
 import (
 	"context"
 	"database/sql"
+	"errors"
 	"fmt"
 	"testing"
 	"time"
@@ -10,8 +12,13 @@ import (
 	"sneak.berlin/go/vaultik/internal/types"
 )
 
+// errTxIntentionalRollback forces a transaction rollback in tests.
+var errTxIntentionalRollback = errors.New("intentional rollback")
+
 // TestFileRepositoryUUIDGeneration tests that files get unique UUIDs
 func TestFileRepositoryUUIDGeneration(t *testing.T) {
+	t.Parallel()
+
 	db, cleanup := setupTestDB(t)
 	defer cleanup()
 
@@ -21,7 +28,7 @@ func TestFileRepositoryUUIDGeneration(t *testing.T) {
 	// Create multiple files
 	files := []*File{
 		{
-			Path:  "/file1.txt",
+			Path:  internalTestFile1,
 			MTime: time.Now().Truncate(time.Second),
 			Size:  1024,
 			Mode:  0644,
@@ -29,7 +36,7 @@ func TestFileRepositoryUUIDGeneration(t *testing.T) {
 			GID:   1000,
 		},
 		{
-			Path:  "/file2.txt",
+			Path:  internalTestFile2,
 			MTime: time.Now().Truncate(time.Second),
 			Size:  2048,
 			Mode:  0644,
@@ -39,6 +46,7 @@ func TestFileRepositoryUUIDGeneration(t *testing.T) {
 	}
 
 	uuids := make(map[string]bool)
+
 	for _, file := range files {
 		err := repo.Create(ctx, nil, file)
 		if err != nil {
@@ -54,12 +62,15 @@ func TestFileRepositoryUUIDGeneration(t *testing.T) {
 		if uuids[file.ID.String()] {
 			t.Errorf("duplicate UUID generated: %s", file.ID)
 		}
+
 		uuids[file.ID.String()] = true
 	}
 }
 
 // TestFileRepositoryGetByID tests retrieving files by UUID
 func TestFileRepositoryGetByID(t *testing.T) {
+	t.Parallel()
+
 	db, cleanup := setupTestDB(t)
 	defer cleanup()
 
@@ -68,7 +79,7 @@ func TestFileRepositoryGetByID(t *testing.T) {
 
 	// Create a file
 	file := &File{
-		Path:  "/test.txt",
+		Path:  internalTestFilePath,
 		MTime: time.Now().Truncate(time.Second),
 		Size:  1024,
 		Mode:  0644,
@@ -90,16 +101,20 @@ func TestFileRepositoryGetByID(t *testing.T) {
 	if retrieved.ID != file.ID {
 		t.Errorf("ID mismatch: expected %s, got %s", file.ID, retrieved.ID)
 	}
+
 	if retrieved.Path != file.Path {
 		t.Errorf("Path mismatch: expected %s, got %s", file.Path, retrieved.Path)
 	}
 
-	// Test non-existent ID
-	nonExistentID := types.NewFileID() // Generate a new UUID that won't exist in the database
+	// Test non-existent ID: generate a new UUID that won't exist in the
+	// database.
+	nonExistentID := types.NewFileID()
+
 	nonExistent, err := repo.GetByID(ctx, nonExistentID)
 	if err != nil {
 		t.Fatalf("GetByID should not return error for non-existent ID: %v", err)
 	}
+
 	if nonExistent != nil {
 		t.Error("expected nil for non-existent ID")
 	}
@@ -107,6 +122,8 @@ func TestFileRepositoryGetByID(t *testing.T) {
 
 // TestOrphanedFileCleanup tests the cleanup of orphaned files
 func TestOrphanedFileCleanup(t *testing.T) {
+	t.Parallel()
+
 	db, cleanup := setupTestDB(t)
 	defer cleanup()
 
@@ -135,6 +152,7 @@ func TestOrphanedFileCleanup(t *testing.T) {
 	if err != nil {
 		t.Fatalf("failed to create file1: %v", err)
 	}
+
 	err = repos.Files.Create(ctx, nil, file2)
 	if err != nil {
 		t.Fatalf("failed to create file2: %v", err)
@@ -142,20 +160,18 @@ func TestOrphanedFileCleanup(t *testing.T) {
 
 	// Create a snapshot and reference only file2
 	snapshot := &Snapshot{
-		ID:        "test-snapshot",
-		Hostname:  "test-host",
+		ID:        internalTestSnapshotID,
+		Hostname:  internalTestHost,
 		StartedAt: time.Now(),
 	}
+
 	err = repos.Snapshots.Create(ctx, nil, snapshot)
 	if err != nil {
 		t.Fatalf("failed to create snapshot: %v", err)
 	}
 
 	// Add file2 to snapshot
-	err = repos.Snapshots.AddFileByID(ctx, nil, snapshot.ID.String(), file2.ID)
-	if err != nil {
-		t.Fatalf("failed to add file to snapshot: %v", err)
-	}
+	mustAddFileToSnapshot(t, repos, snapshot.ID.String(), file2.ID)
 
 	// Run orphaned cleanup
 	err = repos.Files.DeleteOrphaned(ctx)
@@ -168,6 +184,7 @@ func TestOrphanedFileCleanup(t *testing.T) {
 	if err != nil {
 		t.Fatalf("error getting file: %v", err)
 	}
+
 	if orphanedFile != nil {
 		t.Error("orphaned file should have been deleted")
 	}
@@ -177,6 +194,7 @@ func TestOrphanedFileCleanup(t *testing.T) {
 	if err != nil {
 		t.Fatalf("error getting file: %v", err)
 	}
+
 	if referencedFile == nil {
 		t.Error("referenced file should not have been deleted")
 	}
@@ -184,6 +202,8 @@ func TestOrphanedFileCleanup(t *testing.T) {
 
 // TestOrphanedChunkCleanup tests the cleanup of orphaned chunks
 func TestOrphanedChunkCleanup(t *testing.T) {
+	t.Parallel()
+
 	db, cleanup := setupTestDB(t)
 	defer cleanup()
 
@@ -204,6 +224,7 @@ func TestOrphanedChunkCleanup(t *testing.T) {
 	if err != nil {
 		t.Fatalf("failed to create chunk1: %v", err)
 	}
+
 	err = repos.Chunks.Create(ctx, nil, chunk2)
 	if err != nil {
 		t.Fatalf("failed to create chunk2: %v", err)
@@ -211,13 +232,14 @@ func TestOrphanedChunkCleanup(t *testing.T) {
 
 	// Create a file and reference only chunk2
 	file := &File{
-		Path:  "/test.txt",
+		Path:  internalTestFilePath,
 		MTime: time.Now().Truncate(time.Second),
 		Size:  1024,
 		Mode:  0644,
 		UID:   1000,
 		GID:   1000,
 	}
+
 	err = repos.Files.Create(ctx, nil, file)
 	if err != nil {
 		t.Fatalf("failed to create file: %v", err)
@@ -229,6 +251,7 @@ func TestOrphanedChunkCleanup(t *testing.T) {
 		Idx:       0,
 		ChunkHash: chunk2.ChunkHash,
 	}
+
 	err = repos.FileChunks.Create(ctx, nil, fc)
 	if err != nil {
 		t.Fatalf("failed to create file chunk: %v", err)
@@ -245,6 +268,7 @@ func TestOrphanedChunkCleanup(t *testing.T) {
 	if err != nil {
 		t.Fatalf("error getting chunk: %v", err)
 	}
+
 	if orphanedChunk != nil {
 		t.Error("orphaned chunk should have been deleted")
 	}
@@ -254,6 +278,7 @@ func TestOrphanedChunkCleanup(t *testing.T) {
 	if err != nil {
 		t.Fatalf("error getting chunk: %v", err)
 	}
+
 	if referencedChunk == nil {
 		t.Error("referenced chunk should not have been deleted")
 	}
@@ -261,6 +286,8 @@ func TestOrphanedChunkCleanup(t *testing.T) {
 
 // TestOrphanedBlobCleanup tests the cleanup of orphaned blobs
 func TestOrphanedBlobCleanup(t *testing.T) {
+	t.Parallel()
+
 	db, cleanup := setupTestDB(t)
 	defer cleanup()
 
@@ -283,6 +310,7 @@ func TestOrphanedBlobCleanup(t *testing.T) {
 	if err != nil {
 		t.Fatalf("failed to create blob1: %v", err)
 	}
+
 	err = repos.Blobs.Create(ctx, nil, blob2)
 	if err != nil {
 		t.Fatalf("failed to create blob2: %v", err)
@@ -290,10 +318,11 @@ func TestOrphanedBlobCleanup(t *testing.T) {
 
 	// Create a snapshot and reference only blob2
 	snapshot := &Snapshot{
-		ID:        "test-snapshot",
-		Hostname:  "test-host",
+		ID:        internalTestSnapshotID,
+		Hostname:  internalTestHost,
 		StartedAt: time.Now(),
 	}
+
 	err = repos.Snapshots.Create(ctx, nil, snapshot)
 	if err != nil {
 		t.Fatalf("failed to create snapshot: %v", err)
@@ -316,6 +345,7 @@ func TestOrphanedBlobCleanup(t *testing.T) {
 	if err != nil {
 		t.Fatalf("error getting blob: %v", err)
 	}
+
 	if orphanedBlob != nil {
 		t.Error("orphaned blob should have been deleted")
 	}
@@ -325,6 +355,7 @@ func TestOrphanedBlobCleanup(t *testing.T) {
 	if err != nil {
 		t.Fatalf("error getting blob: %v", err)
 	}
+
 	if referencedBlob == nil {
 		t.Error("referenced blob should not have been deleted")
 	}
@@ -332,6 +363,8 @@ func TestOrphanedBlobCleanup(t *testing.T) {
 
 // TestFileChunkRepositoryWithUUIDs tests file-chunk relationships with UUIDs
 func TestFileChunkRepositoryWithUUIDs(t *testing.T) {
+	t.Parallel()
+
 	db, cleanup := setupTestDB(t)
 	defer cleanup()
 
@@ -340,17 +373,15 @@ func TestFileChunkRepositoryWithUUIDs(t *testing.T) {
 
 	// Create a file
 	file := &File{
-		Path:  "/test.txt",
+		Path:  internalTestFilePath,
 		MTime: time.Now().Truncate(time.Second),
 		Size:  3072,
 		Mode:  0644,
 		UID:   1000,
 		GID:   1000,
 	}
-	err := repos.Files.Create(ctx, nil, file)
-	if err != nil {
-		t.Fatalf("failed to create file: %v", err)
-	}
+
+	mustCreateFileRow(t, repos, file)
 
 	// Create chunks
 	chunks := []types.ChunkHash{"chunk1", "chunk2", "chunk3"}
@@ -359,7 +390,8 @@ func TestFileChunkRepositoryWithUUIDs(t *testing.T) {
 			ChunkHash: chunkHash,
 			Size:      1024,
 		}
-		err = repos.Chunks.Create(ctx, nil, chunk)
+
+		err := repos.Chunks.Create(ctx, nil, chunk)
 		if err != nil {
 			t.Fatalf("failed to create chunk: %v", err)
 		}
@@ -370,6 +402,7 @@ func TestFileChunkRepositoryWithUUIDs(t *testing.T) {
 			Idx:       i,
 			ChunkHash: chunkHash,
 		}
+
 		err = repos.FileChunks.Create(ctx, nil, fc)
 		if err != nil {
 			t.Fatalf("failed to create file chunk: %v", err)
@@ -381,6 +414,7 @@ func TestFileChunkRepositoryWithUUIDs(t *testing.T) {
 	if err != nil {
 		t.Fatalf("failed to get file chunks: %v", err)
 	}
+
 	if len(fileChunks) != 3 {
 		t.Errorf("expected 3 chunks, got %d", len(fileChunks))
 	}
@@ -395,6 +429,7 @@ func TestFileChunkRepositoryWithUUIDs(t *testing.T) {
 	if err != nil {
 		t.Fatalf("failed to get file chunks after delete: %v", err)
 	}
+
 	if len(fileChunks) != 0 {
 		t.Errorf("expected 0 chunks after delete, got %d", len(fileChunks))
 	}
@@ -402,6 +437,8 @@ func TestFileChunkRepositoryWithUUIDs(t *testing.T) {
 
 // TestChunkFileRepositoryWithUUIDs tests chunk-file relationships with UUIDs
 func TestChunkFileRepositoryWithUUIDs(t *testing.T) {
+	t.Parallel()
+
 	db, cleanup := setupTestDB(t)
 	defer cleanup()
 
@@ -410,7 +447,7 @@ func TestChunkFileRepositoryWithUUIDs(t *testing.T) {
 
 	// Create files
 	file1 := &File{
-		Path:  "/file1.txt",
+		Path:  internalTestFile1,
 		MTime: time.Now().Truncate(time.Second),
 		Size:  1024,
 		Mode:  0644,
@@ -418,7 +455,7 @@ func TestChunkFileRepositoryWithUUIDs(t *testing.T) {
 		GID:   1000,
 	}
 	file2 := &File{
-		Path:  "/file2.txt",
+		Path:  internalTestFile2,
 		MTime: time.Now().Truncate(time.Second),
 		Size:  1024,
 		Mode:  0644,
@@ -426,21 +463,16 @@ func TestChunkFileRepositoryWithUUIDs(t *testing.T) {
 		GID:   1000,
 	}
 
-	err := repos.Files.Create(ctx, nil, file1)
-	if err != nil {
-		t.Fatalf("failed to create file1: %v", err)
-	}
-	err = repos.Files.Create(ctx, nil, file2)
-	if err != nil {
-		t.Fatalf("failed to create file2: %v", err)
-	}
+	mustCreateFileRow(t, repos, file1)
+	mustCreateFileRow(t, repos, file2)
 
 	// Create a chunk that appears in both files (deduplication)
 	chunk := &Chunk{
 		ChunkHash: types.ChunkHash("shared-chunk"),
 		Size:      1024,
 	}
-	err = repos.Chunks.Create(ctx, nil, chunk)
+
+	err := repos.Chunks.Create(ctx, nil, chunk)
 	if err != nil {
 		t.Fatalf("failed to create chunk: %v", err)
 	}
@@ -463,6 +495,7 @@ func TestChunkFileRepositoryWithUUIDs(t *testing.T) {
 	if err != nil {
 		t.Fatalf("failed to create chunk file 1: %v", err)
 	}
+
 	err = repos.ChunkFiles.Create(ctx, nil, cf2)
 	if err != nil {
 		t.Fatalf("failed to create chunk file 2: %v", err)
@@ -473,6 +506,7 @@ func TestChunkFileRepositoryWithUUIDs(t *testing.T) {
 	if err != nil {
 		t.Fatalf("failed to get chunk files: %v", err)
 	}
+
 	if len(chunkFiles) != 2 {
 		t.Errorf("expected 2 files for chunk, got %d", len(chunkFiles))
 	}
@@ -482,6 +516,7 @@ func TestChunkFileRepositoryWithUUIDs(t *testing.T) {
 	if err != nil {
 		t.Fatalf("failed to get chunks by file ID: %v", err)
 	}
+
 	if len(chunkFiles) != 1 {
 		t.Errorf("expected 1 chunk for file, got %d", len(chunkFiles))
 	}
@@ -489,6 +524,8 @@ func TestChunkFileRepositoryWithUUIDs(t *testing.T) {
 
 // TestSnapshotRepositoryExtendedFields tests snapshot with version and git revision
 func TestSnapshotRepositoryExtendedFields(t *testing.T) {
+	t.Parallel()
+
 	db, cleanup := setupTestDB(t)
 	defer cleanup()
 
@@ -498,7 +535,7 @@ func TestSnapshotRepositoryExtendedFields(t *testing.T) {
 	// Create snapshot with extended fields
 	snapshot := &Snapshot{
 		ID:                   "test-20250722-120000Z",
-		Hostname:             "test-host",
+		Hostname:             internalTestHost,
 		VaultikVersion:       "0.0.1",
 		VaultikGitRevision:   "abc123def456",
 		StartedAt:            time.Now(),
@@ -526,31 +563,39 @@ func TestSnapshotRepositoryExtendedFields(t *testing.T) {
 	}
 
 	if retrieved.VaultikVersion != snapshot.VaultikVersion {
-		t.Errorf("version mismatch: expected %s, got %s", snapshot.VaultikVersion, retrieved.VaultikVersion)
+		t.Errorf("version mismatch: expected %s, got %s",
+			snapshot.VaultikVersion, retrieved.VaultikVersion)
 	}
+
 	if retrieved.VaultikGitRevision != snapshot.VaultikGitRevision {
-		t.Errorf("git revision mismatch: expected %s, got %s", snapshot.VaultikGitRevision, retrieved.VaultikGitRevision)
+		t.Errorf("git revision mismatch: expected %s, got %s",
+			snapshot.VaultikGitRevision, retrieved.VaultikGitRevision)
 	}
+
 	if retrieved.CompressionLevel != snapshot.CompressionLevel {
-		t.Errorf("compression level mismatch: expected %d, got %d", snapshot.CompressionLevel, retrieved.CompressionLevel)
+		t.Errorf("compression level mismatch: expected %d, got %d",
+			snapshot.CompressionLevel, retrieved.CompressionLevel)
 	}
+
 	if retrieved.BlobUncompressedSize != snapshot.BlobUncompressedSize {
-		t.Errorf("uncompressed size mismatch: expected %d, got %d", snapshot.BlobUncompressedSize, retrieved.BlobUncompressedSize)
+		t.Errorf("uncompressed size mismatch: expected %d, got %d",
+			snapshot.BlobUncompressedSize, retrieved.BlobUncompressedSize)
 	}
+
 	if retrieved.UploadDurationMs != snapshot.UploadDurationMs {
-		t.Errorf("upload duration mismatch: expected %d, got %d", snapshot.UploadDurationMs, retrieved.UploadDurationMs)
+		t.Errorf("upload duration mismatch: expected %d, got %d",
+			snapshot.UploadDurationMs, retrieved.UploadDurationMs)
 	}
 }
 
 // TestComplexOrphanedDataScenario tests a complex scenario with multiple relationships
-func TestComplexOrphanedDataScenario(t *testing.T) {
-	db, cleanup := setupTestDB(t)
-	defer cleanup()
+// createOrphanScenarioFixtures creates two snapshots and three files for
+// the orphaned-data cleanup scenario.
+func createOrphanScenarioFixtures(
+	ctx context.Context, t *testing.T, repos *Repositories,
+) (*Snapshot, *Snapshot, []*File) {
+	t.Helper()
 
-	ctx := context.Background()
-	repos := NewRepositories(db)
-
-	// Create snapshots
 	snapshot1 := &Snapshot{
 		ID:        "snapshot1",
 		Hostname:  "host1",
@@ -566,6 +611,7 @@ func TestComplexOrphanedDataScenario(t *testing.T) {
 	if err != nil {
 		t.Fatalf("failed to create snapshot1: %v", err)
 	}
+
 	err = repos.Snapshots.Create(ctx, nil, snapshot2)
 	if err != nil {
 		t.Fatalf("failed to create snapshot2: %v", err)
@@ -582,40 +628,44 @@ func TestComplexOrphanedDataScenario(t *testing.T) {
 			UID:   1000,
 			GID:   1000,
 		}
+
 		err = repos.Files.Create(ctx, nil, files[i])
 		if err != nil {
 			t.Fatalf("failed to create file%d: %v", i, err)
 		}
 	}
 
+	return snapshot1, snapshot2, files
+}
+
+func TestComplexOrphanedDataScenario(t *testing.T) {
+	t.Parallel()
+
+	db, cleanup := setupTestDB(t)
+	defer cleanup()
+
+	ctx := context.Background()
+	repos := NewRepositories(db)
+
+	snapshot1, snapshot2, files := createOrphanScenarioFixtures(ctx, t, repos)
+
 	// Add files to snapshots
 	// Snapshot1: file0, file1
 	// Snapshot2: file1, file2
 	// file0: only in snapshot1
 	// file1: in both snapshots
 	// file2: only in snapshot2
-	err = repos.Snapshots.AddFileByID(ctx, nil, snapshot1.ID.String(), files[0].ID)
-	if err != nil {
-		t.Fatal(err)
-	}
-	err = repos.Snapshots.AddFileByID(ctx, nil, snapshot1.ID.String(), files[1].ID)
-	if err != nil {
-		t.Fatal(err)
-	}
-	err = repos.Snapshots.AddFileByID(ctx, nil, snapshot2.ID.String(), files[1].ID)
-	if err != nil {
-		t.Fatal(err)
-	}
-	err = repos.Snapshots.AddFileByID(ctx, nil, snapshot2.ID.String(), files[2].ID)
+	mustAddFileToSnapshot(t, repos, snapshot1.ID.String(), files[0].ID)
+	mustAddFileToSnapshot(t, repos, snapshot1.ID.String(), files[1].ID)
+	mustAddFileToSnapshot(t, repos, snapshot2.ID.String(), files[1].ID)
+	mustAddFileToSnapshot(t, repos, snapshot2.ID.String(), files[2].ID)
+
+	// Delete snapshot1
+	err := repos.Snapshots.DeleteSnapshotFiles(ctx, snapshot1.ID.String())
 	if err != nil {
 		t.Fatal(err)
 	}
 
-	// Delete snapshot1
-	err = repos.Snapshots.DeleteSnapshotFiles(ctx, snapshot1.ID.String())
-	if err != nil {
-		t.Fatal(err)
-	}
 	err = repos.Snapshots.Delete(ctx, snapshot1.ID.String())
 	if err != nil {
 		t.Fatal(err)
@@ -633,6 +683,7 @@ func TestComplexOrphanedDataScenario(t *testing.T) {
 	if err != nil {
 		t.Fatalf("error getting file0: %v", err)
 	}
+
 	if file0 != nil {
 		t.Error("file0 should have been deleted")
 	}
@@ -642,6 +693,7 @@ func TestComplexOrphanedDataScenario(t *testing.T) {
 	if err != nil {
 		t.Fatalf("error getting file1: %v", err)
 	}
+
 	if file1 == nil {
 		t.Error("file1 should still exist")
 	}
@@ -651,6 +703,7 @@ func TestComplexOrphanedDataScenario(t *testing.T) {
 	if err != nil {
 		t.Fatalf("error getting file2: %v", err)
 	}
+
 	if file2 == nil {
 		t.Error("file2 should still exist")
 	}
@@ -658,6 +711,8 @@ func TestComplexOrphanedDataScenario(t *testing.T) {
 
 // TestCascadeDelete tests that cascade deletes work properly
 func TestCascadeDelete(t *testing.T) {
+	t.Parallel()
+
 	db, cleanup := setupTestDB(t)
 	defer cleanup()
 
@@ -673,17 +728,19 @@ func TestCascadeDelete(t *testing.T) {
 		UID:   1000,
 		GID:   1000,
 	}
+
 	err := repos.Files.Create(ctx, nil, file)
 	if err != nil {
 		t.Fatalf("failed to create file: %v", err)
 	}
 
 	// Create chunks and file-chunk mappings
-	for i := 0; i < 3; i++ {
+	for i := range 3 {
 		chunk := &Chunk{
 			ChunkHash: types.ChunkHash(fmt.Sprintf("cascade-chunk-%d", i)),
 			Size:      1024,
 		}
+
 		err = repos.Chunks.Create(ctx, nil, chunk)
 		if err != nil {
 			t.Fatalf("failed to create chunk: %v", err)
@@ -694,6 +751,7 @@ func TestCascadeDelete(t *testing.T) {
 			Idx:       i,
 			ChunkHash: chunk.ChunkHash,
 		}
+
 		err = repos.FileChunks.Create(ctx, nil, fc)
 		if err != nil {
 			t.Fatalf("failed to create file chunk: %v", err)
@@ -705,6 +763,7 @@ func TestCascadeDelete(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
+
 	if len(fileChunks) != 3 {
 		t.Errorf("expected 3 file chunks, got %d", len(fileChunks))
 	}
@@ -720,6 +779,7 @@ func TestCascadeDelete(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
+
 	if len(fileChunks) != 0 {
 		t.Errorf("expected 0 file chunks after cascade delete, got %d", len(fileChunks))
 	}
@@ -727,6 +787,8 @@ func TestCascadeDelete(t *testing.T) {
 
 // TestTransactionIsolation tests that transactions properly isolate changes
 func TestTransactionIsolation(t *testing.T) {
+	t.Parallel()
+
 	db, cleanup := setupTestDB(t)
 	defer cleanup()
 
@@ -744,6 +806,7 @@ func TestTransactionIsolation(t *testing.T) {
 			UID:   1000,
 			GID:   1000,
 		}
+
 		err := repos.Files.Create(ctx, tx, file)
 		if err != nil {
 			return err
@@ -754,9 +817,8 @@ func TestTransactionIsolation(t *testing.T) {
 		// For now, we'll just test that rollback works
 
 		// Return an error to trigger rollback
-		return fmt.Errorf("intentional rollback")
+		return errTxIntentionalRollback
 	})
-
 	if err == nil {
 		t.Fatal("expected error from transaction")
 	}
@@ -766,37 +828,22 @@ func TestTransactionIsolation(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
+
 	if len(files) != 0 {
 		t.Error("file should not exist after rollback")
 	}
 }
 
-// TestConcurrentOrphanedCleanup tests that concurrent cleanup operations don't interfere
-func TestConcurrentOrphanedCleanup(t *testing.T) {
-	db, cleanup := setupTestDB(t)
-	defer cleanup()
+// TestConcurrentOrphanedCleanup tests that concurrent cleanup operations
+// don't interfere.
+// createConcurrentCleanupFiles creates 20 files and associates the
+// even-numbered ones with the snapshot, leaving the rest orphaned.
+func createConcurrentCleanupFiles(
+	ctx context.Context, t *testing.T, repos *Repositories, snapshotID string,
+) {
+	t.Helper()
 
-	ctx := context.Background()
-	repos := NewRepositories(db)
-
-	// Set a 5-second busy timeout to handle concurrent operations
-	if _, err := db.conn.Exec("PRAGMA busy_timeout = 5000"); err != nil {
-		t.Fatalf("failed to set busy timeout: %v", err)
-	}
-
-	// Create a snapshot
-	snapshot := &Snapshot{
-		ID:        "concurrent-test",
-		Hostname:  "test-host",
-		StartedAt: time.Now(),
-	}
-	err := repos.Snapshots.Create(ctx, nil, snapshot)
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	// Create many files, some orphaned
-	for i := 0; i < 20; i++ {
+	for i := range 20 {
 		file := &File{
 			Path:  types.FilePath(fmt.Sprintf("/concurrent-%d.txt", i)),
 			MTime: time.Now().Truncate(time.Second),
@@ -805,31 +852,63 @@ func TestConcurrentOrphanedCleanup(t *testing.T) {
 			UID:   1000,
 			GID:   1000,
 		}
-		err = repos.Files.Create(ctx, nil, file)
+
+		err := repos.Files.Create(ctx, nil, file)
 		if err != nil {
 			t.Fatal(err)
 		}
 
 		// Add even-numbered files to snapshot
 		if i%2 == 0 {
-			err = repos.Snapshots.AddFileByID(ctx, nil, snapshot.ID.String(), file.ID)
+			err = repos.Snapshots.AddFileByID(ctx, nil, snapshotID, file.ID)
 			if err != nil {
 				t.Fatal(err)
 			}
 		}
 	}
+}
+
+func TestConcurrentOrphanedCleanup(t *testing.T) {
+	t.Parallel()
+
+	db, cleanup := setupTestDB(t)
+	defer cleanup()
+
+	ctx := context.Background()
+	repos := NewRepositories(db)
+
+	// Set a 5-second busy timeout to handle concurrent operations
+	_, err := db.conn.ExecContext(ctx, "PRAGMA busy_timeout = 5000")
+	if err != nil {
+		t.Fatalf("failed to set busy timeout: %v", err)
+	}
+
+	// Create a snapshot
+	snapshot := &Snapshot{
+		ID:        "concurrent-test",
+		Hostname:  internalTestHost,
+		StartedAt: time.Now(),
+	}
+
+	err = repos.Snapshots.Create(ctx, nil, snapshot)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	createConcurrentCleanupFiles(ctx, t, repos, snapshot.ID.String())
 
 	// Run multiple cleanup operations concurrently
 	// Note: SQLite has limited support for concurrent writes, so we expect some to fail
 	done := make(chan error, 3)
-	for i := 0; i < 3; i++ {
+
+	for range 3 {
 		go func() {
 			done <- repos.Files.DeleteOrphaned(ctx)
 		}()
 	}
 
 	// Wait for all to complete
-	for i := 0; i < 3; i++ {
+	for i := range 3 {
 		err := <-done
 		if err != nil {
 			t.Errorf("cleanup %d failed: %v", i, err)
@@ -850,10 +929,12 @@ func TestConcurrentOrphanedCleanup(t *testing.T) {
 	// Verify all remaining files are even-numbered
 	for _, file := range files {
 		var num int
+
 		_, err := fmt.Sscanf(file.Path.String(), "/concurrent-%d.txt", &num)
 		if err != nil {
 			t.Logf("failed to parse file number from %s: %v", file.Path, err)
 		}
+
 		if num%2 != 0 {
 			t.Errorf("odd-numbered file %s should have been deleted", file.Path)
 		}

internal/database/repository_debug_test.go

@@ -1,3 +1,4 @@
+//nolint:testpackage // inspects the unexported database connection
 package database
 
 import (
@@ -6,15 +7,50 @@ import (
 	"time"
 )
 
-// TestOrphanedFileCleanupDebug tests orphaned file cleanup with debug output
-func TestOrphanedFileCleanupDebug(t *testing.T) {
-	db, cleanup := setupTestDB(t)
-	defer cleanup()
+// logSnapshotFileIDs logs every file_id present in snapshot_files.
+func logSnapshotFileIDs(t *testing.T, db *DB) {
+	t.Helper()
 
 	ctx := context.Background()
-	repos := NewRepositories(db)
 
-	// Create files
+	rows, err := db.conn.QueryContext(ctx, "SELECT file_id FROM snapshot_files")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer func() {
+		err := rows.Close()
+		if err != nil {
+			t.Logf("failed to close rows: %v", err)
+		}
+	}()
+
+	t.Log("Files in snapshot_files:")
+
+	for rows.Next() {
+		var fileID string
+
+		err := rows.Scan(&fileID)
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		t.Logf("  - %s", fileID)
+	}
+
+	err = rows.Err()
+	if err != nil {
+		t.Fatal(err)
+	}
+}
+
+// TestOrphanedFileCleanupDebug tests orphaned file cleanup with debug output
+// createOrphanDebugFixtures creates one orphaned file, one referenced
+// file, and the snapshot that will reference the latter.
+func createOrphanDebugFixtures(
+	ctx context.Context, t *testing.T, repos *Repositories,
+) (*File, *File, *Snapshot) {
+	t.Helper()
+
 	file1 := &File{
 		Path:  "/orphaned.txt",
 		MTime: time.Now().Truncate(time.Second),
@@ -36,72 +72,65 @@ func TestOrphanedFileCleanupDebug(t *testing.T) {
 	if err != nil {
 		t.Fatalf("failed to create file1: %v", err)
 	}
+
 	t.Logf("Created file1 with ID: %s", file1.ID)
 
 	err = repos.Files.Create(ctx, nil, file2)
 	if err != nil {
 		t.Fatalf("failed to create file2: %v", err)
 	}
+
 	t.Logf("Created file2 with ID: %s", file2.ID)
 
 	// Create a snapshot and reference only file2
 	snapshot := &Snapshot{
-		ID:        "test-snapshot",
-		Hostname:  "test-host",
+		ID:        internalTestSnapshotID,
+		Hostname:  internalTestHost,
 		StartedAt: time.Now(),
 	}
+
 	err = repos.Snapshots.Create(ctx, nil, snapshot)
 	if err != nil {
 		t.Fatalf("failed to create snapshot: %v", err)
 	}
+
 	t.Logf("Created snapshot: %s", snapshot.ID)
 
+	return file1, file2, snapshot
+}
+
+func TestOrphanedFileCleanupDebug(t *testing.T) {
+	t.Parallel()
+
+	db, cleanup := setupTestDB(t)
+	defer cleanup()
+
+	ctx := context.Background()
+	repos := NewRepositories(db)
+
+	file1, file2, snapshot := createOrphanDebugFixtures(ctx, t, repos)
+
 	// Check snapshot_files before adding
-	var count int
-	err = db.conn.QueryRow("SELECT COUNT(*) FROM snapshot_files").Scan(&count)
-	if err != nil {
-		t.Fatal(err)
-	}
+	count := countRow(t, db, "SELECT COUNT(*) FROM snapshot_files")
 	t.Logf("snapshot_files count before add: %d", count)
 
 	// Add file2 to snapshot
-	err = repos.Snapshots.AddFileByID(ctx, nil, snapshot.ID.String(), file2.ID)
+	err := repos.Snapshots.AddFileByID(ctx, nil, snapshot.ID.String(), file2.ID)
 	if err != nil {
 		t.Fatalf("failed to add file to snapshot: %v", err)
 	}
+
 	t.Logf("Added file2 to snapshot")
 
 	// Check snapshot_files after adding
-	err = db.conn.QueryRow("SELECT COUNT(*) FROM snapshot_files").Scan(&count)
-	if err != nil {
-		t.Fatal(err)
-	}
+	count = countRow(t, db, "SELECT COUNT(*) FROM snapshot_files")
 	t.Logf("snapshot_files count after add: %d", count)
 
 	// Check which files are referenced
-	rows, err := db.conn.Query("SELECT file_id FROM snapshot_files")
-	if err != nil {
-		t.Fatal(err)
-	}
-	defer func() {
-		if err := rows.Close(); err != nil {
-			t.Logf("failed to close rows: %v", err)
-		}
-	}()
-	t.Log("Files in snapshot_files:")
-	for rows.Next() {
-		var fileID string
-		if err := rows.Scan(&fileID); err != nil {
-			t.Fatal(err)
-		}
-		t.Logf("  - %s", fileID)
-	}
+	logSnapshotFileIDs(t, db)
 
 	// Check files before cleanup
-	err = db.conn.QueryRow("SELECT COUNT(*) FROM files").Scan(&count)
-	if err != nil {
-		t.Fatal(err)
-	}
+	count = countRow(t, db, countFilesQuery)
 	t.Logf("Files count before cleanup: %d", count)
 
 	// Run orphaned cleanup
@@ -109,13 +138,11 @@ func TestOrphanedFileCleanupDebug(t *testing.T) {
 	if err != nil {
 		t.Fatalf("failed to delete orphaned files: %v", err)
 	}
+
 	t.Log("Ran orphaned cleanup")
 
 	// Check files after cleanup
-	err = db.conn.QueryRow("SELECT COUNT(*) FROM files").Scan(&count)
-	if err != nil {
-		t.Fatal(err)
-	}
+	count = countRow(t, db, countFilesQuery)
 	t.Logf("Files count after cleanup: %d", count)
 
 	// List remaining files
@@ -123,7 +150,9 @@ func TestOrphanedFileCleanupDebug(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
+
 	t.Log("Remaining files:")
+
 	for _, f := range files {
 		t.Logf("  - ID: %s, Path: %s", f.ID, f.Path)
 	}
@@ -133,19 +162,16 @@ func TestOrphanedFileCleanupDebug(t *testing.T) {
 	if err != nil {
 		t.Fatalf("error getting file: %v", err)
 	}
+
 	if orphanedFile != nil {
 		t.Error("orphaned file should have been deleted")
 		// Let's check why it wasn't deleted
-		var exists bool
-		err = db.conn.QueryRow(`
+		stillReferenced := countRow(t, db, `
 			SELECT EXISTS(
 				SELECT 1 FROM snapshot_files
 				WHERE file_id = ?
-			)`, file1.ID).Scan(&exists)
-		if err != nil {
-			t.Fatal(err)
-		}
-		t.Logf("File1 exists in snapshot_files: %v", exists)
+			)`, file1.ID)
+		t.Logf("File1 exists in snapshot_files: %v", stillReferenced != 0)
 	} else {
 		t.Log("Orphaned file was correctly deleted")
 	}
@@ -155,6 +181,7 @@ func TestOrphanedFileCleanupDebug(t *testing.T) {
 	if err != nil {
 		t.Fatalf("error getting file: %v", err)
 	}
+
 	if referencedFile == nil {
 		t.Error("referenced file should not have been deleted")
 	} else {

internal/database/repository_edge_cases_test.go

@@ -1,3 +1,4 @@
+//nolint:testpackage // inspects the unexported database connection
 package database
 
 import (
@@ -10,20 +11,17 @@ import (
 	"sneak.berlin/go/vaultik/internal/types"
 )
 
-// TestFileRepositoryEdgeCases tests edge cases for file repository
-func TestFileRepositoryEdgeCases(t *testing.T) {
-	db, cleanup := setupTestDB(t)
-	defer cleanup()
-
-	ctx := context.Background()
-	repo := NewFileRepository(db)
-
-	tests := []struct {
+// fileEdgeCase describes one Create edge-case scenario.
+type fileEdgeCase struct {
 	name    string
 	file    *File
 	wantErr bool
 	errMsg  string
-	}{
+}
+
+// fileEdgeCases returns the Create edge-case table.
+func fileEdgeCases() []fileEdgeCase {
+	return []fileEdgeCase{
 		{
 			name: "empty path",
 			file: &File{
@@ -51,6 +49,7 @@ func TestFileRepositoryEdgeCases(t *testing.T) {
 		{
 			name: "path with special characters",
 			file: &File{
+				//nolint:gosmopolitan // non-ASCII path is deliberate test data
 				Path:  "/test/file with spaces and 特殊文字.txt",
 				MTime: time.Now(),
 				Size:  1024,
@@ -86,18 +85,33 @@ func TestFileRepositoryEdgeCases(t *testing.T) {
 			wantErr: false,
 		},
 	}
+}
 
-	for i, tt := range tests {
+// TestFileRepositoryEdgeCases tests edge cases for file repository
+func TestFileRepositoryEdgeCases(t *testing.T) {
+	t.Parallel()
+
+	db, cleanup := setupTestDB(t)
+	t.Cleanup(cleanup)
+
+	ctx := context.Background()
+	repo := NewFileRepository(db)
+
+	for i, tt := range fileEdgeCases() {
 		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
+
 			// Add a unique suffix to paths to avoid UNIQUE constraint violations
 			if tt.file.Path != "" {
-				tt.file.Path = types.FilePath(fmt.Sprintf("%s_%d_%d", tt.file.Path, i, time.Now().UnixNano()))
+				tt.file.Path = types.FilePath(fmt.Sprintf("%s_%d_%d",
+					tt.file.Path, i, time.Now().UnixNano()))
 			}
 
 			err := repo.Create(ctx, nil, tt.file)
 			if (err != nil) != tt.wantErr {
 				t.Errorf("Create() error = %v, wantErr %v", err, tt.wantErr)
 			}
+
 			if err != nil && tt.errMsg != "" && !strings.Contains(err.Error(), tt.errMsg) {
 				t.Errorf("Create() error = %v, want error containing %q", err, tt.errMsg)
 			}
@@ -105,16 +119,12 @@ func TestFileRepositoryEdgeCases(t *testing.T) {
 	}
 }
 
-// TestDuplicateHandling tests handling of duplicate entries
-func TestDuplicateHandling(t *testing.T) {
-	db, cleanup := setupTestDB(t)
-	defer cleanup()
+// testDuplicateFilePaths exercises the UPSERT behavior for duplicate paths.
+func testDuplicateFilePaths(t *testing.T, repos *Repositories) {
+	t.Helper()
 
 	ctx := context.Background()
-	repos := NewRepositories(db)
 
-	// Test duplicate file paths - Create uses UPSERT logic
-	t.Run("duplicate file paths", func(t *testing.T) {
 	file1 := &File{
 		Path:  "/duplicate.txt",
 		MTime: time.Now(),
@@ -136,6 +146,7 @@ func TestDuplicateHandling(t *testing.T) {
 	if err != nil {
 		t.Fatalf("failed to create file1: %v", err)
 	}
+
 	originalID := file1.ID
 
 	// Create with same path should update the existing record (UPSERT behavior)
@@ -157,31 +168,17 @@ func TestDuplicateHandling(t *testing.T) {
 
 	// ID might be different due to the UPSERT
 	if retrievedFile.ID != file2.ID {
-			t.Logf("File ID changed from %s to %s during upsert", originalID, retrievedFile.ID)
+		t.Logf("File ID changed from %s to %s during upsert",
+			originalID, retrievedFile.ID)
 	}
-	})
+}
 
-	// Test duplicate chunk hashes
-	t.Run("duplicate chunk hashes", func(t *testing.T) {
-		chunk := &Chunk{
-			ChunkHash: types.ChunkHash("duplicate-chunk"),
-			Size:      1024,
-		}
+// testDuplicateFileChunks exercises idempotent file-chunk mapping creation.
+func testDuplicateFileChunks(t *testing.T, repos *Repositories) {
+	t.Helper()
 
-		err := repos.Chunks.Create(ctx, nil, chunk)
-		if err != nil {
-			t.Fatalf("failed to create chunk: %v", err)
-		}
+	ctx := context.Background()
 
-		// Creating the same chunk again should be idempotent (ON CONFLICT DO NOTHING)
-		err = repos.Chunks.Create(ctx, nil, chunk)
-		if err != nil {
-			t.Errorf("duplicate chunk creation should be idempotent, got error: %v", err)
-		}
-	})
-
-	// Test duplicate file-chunk mappings
-	t.Run("duplicate file-chunk mappings", func(t *testing.T) {
 	file := &File{
 		Path:  "/test-dup-fc.txt",
 		MTime: time.Now(),
@@ -190,6 +187,7 @@ func TestDuplicateHandling(t *testing.T) {
 		UID:   1000,
 		GID:   1000,
 	}
+
 	err := repos.Files.Create(ctx, nil, file)
 	if err != nil {
 		t.Fatal(err)
@@ -199,6 +197,7 @@ func TestDuplicateHandling(t *testing.T) {
 		ChunkHash: types.ChunkHash("test-chunk-dup"),
 		Size:      1024,
 	}
+
 	err = repos.Chunks.Create(ctx, nil, chunk)
 	if err != nil {
 		t.Fatal(err)
@@ -220,19 +219,66 @@ func TestDuplicateHandling(t *testing.T) {
 	if err != nil {
 		t.Error("file-chunk creation should be idempotent")
 	}
+}
+
+// TestDuplicateHandling tests handling of duplicate entries
+func TestDuplicateHandling(t *testing.T) {
+	t.Parallel()
+
+	db, cleanup := setupTestDB(t)
+	t.Cleanup(cleanup)
+
+	ctx := context.Background()
+	repos := NewRepositories(db)
+
+	// Test duplicate file paths - Create uses UPSERT logic
+	t.Run("duplicate file paths", func(t *testing.T) {
+		t.Parallel()
+		testDuplicateFilePaths(t, repos)
+	})
+
+	// Test duplicate chunk hashes
+	t.Run("duplicate chunk hashes", func(t *testing.T) {
+		t.Parallel()
+
+		chunk := &Chunk{
+			ChunkHash: types.ChunkHash("duplicate-chunk"),
+			Size:      1024,
+		}
+
+		err := repos.Chunks.Create(ctx, nil, chunk)
+		if err != nil {
+			t.Fatalf("failed to create chunk: %v", err)
+		}
+
+		// Creating the same chunk again should be idempotent (ON CONFLICT DO NOTHING)
+		err = repos.Chunks.Create(ctx, nil, chunk)
+		if err != nil {
+			t.Errorf("duplicate chunk creation should be idempotent, got error: %v", err)
+		}
+	})
+
+	// Test duplicate file-chunk mappings
+	t.Run("duplicate file-chunk mappings", func(t *testing.T) {
+		t.Parallel()
+		testDuplicateFileChunks(t, repos)
 	})
 }
 
 // TestNullHandling tests handling of NULL values
 func TestNullHandling(t *testing.T) {
+	t.Parallel()
+
 	db, cleanup := setupTestDB(t)
-	defer cleanup()
+	t.Cleanup(cleanup)
 
 	ctx := context.Background()
 	repos := NewRepositories(db)
 
 	// Test file with no link target
 	t.Run("file without link target", func(t *testing.T) {
+		t.Parallel()
+
 		file := &File{
 			Path:       "/regular.txt",
 			MTime:      time.Now(),
@@ -260,9 +306,11 @@ func TestNullHandling(t *testing.T) {
 
 	// Test snapshot with NULL completed_at
 	t.Run("incomplete snapshot", func(t *testing.T) {
+		t.Parallel()
+
 		snapshot := &Snapshot{
 			ID:          "incomplete-test",
-			Hostname:    "test-host",
+			Hostname:    internalTestHost,
 			StartedAt:   time.Now(),
 			CompletedAt: nil, // Should remain NULL until completed
 		}
@@ -284,6 +332,18 @@ func TestNullHandling(t *testing.T) {
 
 	// Test blob with NULL uploaded_ts
 	t.Run("blob not uploaded", func(t *testing.T) {
+		t.Parallel()
+		verifyBlobNullUploadTS(ctx, t, repos)
+	})
+}
+
+// verifyBlobNullUploadTS checks that a blob created without an upload
+// timestamp round-trips with UploadedTS nil.
+func verifyBlobNullUploadTS(
+	ctx context.Context, t *testing.T, repos *Repositories,
+) {
+	t.Helper()
+
 	blob := &Blob{
 		ID:         types.NewBlobID(),
 		Hash:       types.BlobHash("test-hash"),
@@ -304,11 +364,54 @@ func TestNullHandling(t *testing.T) {
 	if retrieved.UploadedTS != nil {
 		t.Error("expected nil UploadedTS for non-uploaded blob")
 	}
-	})
+}
+
+// createLargeDatasetFiles creates fileCount files and adds every other
+// one to the snapshot.
+func createLargeDatasetFiles(
+	t *testing.T,
+	repos *Repositories,
+	snapshotID string,
+	fileCount int,
+) {
+	t.Helper()
+
+	ctx := context.Background()
+	start := time.Now()
+
+	for i := range fileCount {
+		file := &File{
+			Path:  types.FilePath(fmt.Sprintf("/large/file%05d.txt", i)),
+			MTime: time.Now(),
+			Size:  int64(i * 1024),
+			Mode:  0644,
+			UID:   uint32(1000 + (i % 10)),
+			GID:   uint32(1000 + (i % 10)),
+		}
+
+		err := repos.Files.Create(ctx, nil, file)
+		if err != nil {
+			t.Fatalf("failed to create file %d: %v", i, err)
+		}
+
+		// Add half to snapshot
+		if i%2 == 0 {
+			err = repos.Snapshots.AddFileByID(ctx, nil, snapshotID, file.ID)
+			if err != nil {
+				t.Fatal(err)
+			}
+		}
+	}
+
+	t.Logf("Created %d files in %v", fileCount, time.Since(start))
 }
 
 // TestLargeDatasets tests operations with large amounts of data
+//
+//nolint:tparallel // subtests share one database and are order-dependent
 func TestLargeDatasets(t *testing.T) {
+	t.Parallel()
+
 	if testing.Short() {
 		t.Skip("skipping large dataset test in short mode")
 	}
@@ -322,9 +425,10 @@ func TestLargeDatasets(t *testing.T) {
 	// Create a snapshot
 	snapshot := &Snapshot{
 		ID:        "large-dataset-test",
-		Hostname:  "test-host",
+		Hostname:  internalTestHost,
 		StartedAt: time.Now(),
 	}
+
 	err := repos.Snapshots.Create(ctx, nil, snapshot)
 	if err != nil {
 		t.Fatal(err)
@@ -332,56 +436,39 @@ func TestLargeDatasets(t *testing.T) {
 
 	// Create many files
 	const fileCount = 1000
-	fileIDs := make([]types.FileID, fileCount)
 
+	//nolint:paralleltest // phases share one database and are order-dependent
 	t.Run("create many files", func(t *testing.T) {
-		start := time.Now()
-		for i := 0; i < fileCount; i++ {
-			file := &File{
-				Path:  types.FilePath(fmt.Sprintf("/large/file%05d.txt", i)),
-				MTime: time.Now(),
-				Size:  int64(i * 1024),
-				Mode:  0644,
-				UID:   uint32(1000 + (i % 10)),
-				GID:   uint32(1000 + (i % 10)),
-			}
-			err := repos.Files.Create(ctx, nil, file)
-			if err != nil {
-				t.Fatalf("failed to create file %d: %v", i, err)
-			}
-			fileIDs[i] = file.ID
-
-			// Add half to snapshot
-			if i%2 == 0 {
-				err = repos.Snapshots.AddFileByID(ctx, nil, snapshot.ID.String(), file.ID)
-				if err != nil {
-					t.Fatal(err)
-				}
-			}
-		}
-		t.Logf("Created %d files in %v", fileCount, time.Since(start))
+		createLargeDatasetFiles(t, repos, snapshot.ID.String(), fileCount)
 	})
 
 	// Test ListByPrefix performance
+	//nolint:paralleltest // phases share one database and are order-dependent
 	t.Run("list by prefix performance", func(t *testing.T) {
 		start := time.Now()
+
 		files, err := repos.Files.ListByPrefix(ctx, "/large/")
 		if err != nil {
 			t.Fatal(err)
 		}
+
 		if len(files) != fileCount {
 			t.Errorf("expected %d files, got %d", fileCount, len(files))
 		}
+
 		t.Logf("Listed %d files in %v", len(files), time.Since(start))
 	})
 
 	// Test orphaned cleanup performance
+	//nolint:paralleltest // phases share one database and are order-dependent
 	t.Run("orphaned cleanup performance", func(t *testing.T) {
 		start := time.Now()
+
 		err := repos.Files.DeleteOrphaned(ctx)
 		if err != nil {
 			t.Fatal(err)
 		}
+
 		t.Logf("Cleaned up orphaned files in %v", time.Since(start))
 
 		// Verify correct number remain
@@ -389,26 +476,33 @@ func TestLargeDatasets(t *testing.T) {
 		if err != nil {
 			t.Fatal(err)
 		}
+
 		if len(files) != fileCount/2 {
-			t.Errorf("expected %d files after cleanup, got %d", fileCount/2, len(files))
+			t.Errorf("expected %d files after cleanup, got %d",
+				fileCount/2, len(files))
 		}
 	})
 }
 
 // TestErrorPropagation tests that errors are properly propagated
 func TestErrorPropagation(t *testing.T) {
+	t.Parallel()
+
 	db, cleanup := setupTestDB(t)
-	defer cleanup()
+	t.Cleanup(cleanup)
 
 	ctx := context.Background()
 	repos := NewRepositories(db)
 
 	// Test GetByID with non-existent ID
 	t.Run("GetByID non-existent", func(t *testing.T) {
+		t.Parallel()
+
 		file, err := repos.Files.GetByID(ctx, types.NewFileID())
 		if err != nil {
 			t.Errorf("GetByID should not return error for non-existent ID, got: %v", err)
 		}
+
 		if file != nil {
 			t.Error("expected nil file for non-existent ID")
 		}
@@ -416,10 +510,14 @@ func TestErrorPropagation(t *testing.T) {
 
 	// Test GetByPath with non-existent path
 	t.Run("GetByPath non-existent", func(t *testing.T) {
+		t.Parallel()
+
 		file, err := repos.Files.GetByPath(ctx, "/non/existent/path.txt")
 		if err != nil {
-			t.Errorf("GetByPath should not return error for non-existent path, got: %v", err)
+			t.Errorf("GetByPath should not return error for non-existent path, got: %v",
+				err)
 		}
+
 		if file != nil {
 			t.Error("expected nil file for non-existent path")
 		}
@@ -427,15 +525,19 @@ func TestErrorPropagation(t *testing.T) {
 
 	// Test invalid foreign key reference
 	t.Run("invalid foreign key", func(t *testing.T) {
+		t.Parallel()
+
 		fc := &FileChunk{
 			FileID:    types.NewFileID(),
 			Idx:       0,
 			ChunkHash: types.ChunkHash("some-chunk"),
 		}
+
 		err := repos.FileChunks.Create(ctx, nil, fc)
 		if err == nil {
 			t.Error("expected error for invalid foreign key")
 		}
+
 		if !strings.Contains(err.Error(), "FOREIGN KEY") {
 			t.Errorf("expected foreign key error, got: %v", err)
 		}
@@ -444,8 +546,10 @@ func TestErrorPropagation(t *testing.T) {
 
 // TestQueryInjection tests that the system is safe from SQL injection
 func TestQueryInjection(t *testing.T) {
+	t.Parallel()
+
 	db, cleanup := setupTestDB(t)
-	defer cleanup()
+	t.Cleanup(cleanup)
 
 	ctx := context.Background()
 	repos := NewRepositories(db)
@@ -460,6 +564,8 @@ func TestQueryInjection(t *testing.T) {
 
 	for _, injection := range injectionTests {
 		t.Run("injection attempt", func(t *testing.T) {
+			t.Parallel()
+
 			// Try injection in file path
 			file := &File{
 				Path:  types.FilePath(injection),
@@ -475,7 +581,8 @@ func TestQueryInjection(t *testing.T) {
 
 			// Verify tables still exist
 			var count int
-			err := db.conn.QueryRow("SELECT COUNT(*) FROM files").Scan(&count)
+
+			err := db.conn.QueryRowContext(ctx, countFilesQuery).Scan(&count)
 			if err != nil {
 				t.Fatal("files table was damaged by injection")
 			}
@@ -485,6 +592,8 @@ func TestQueryInjection(t *testing.T) {
 
 // TestTimezoneHandling tests that times are properly handled in UTC
 func TestTimezoneHandling(t *testing.T) {
+	t.Parallel()
+
 	db, cleanup := setupTestDB(t)
 	defer cleanup()
 

internal/database/snapshots.go

@@ -3,43 +3,60 @@ package database
 import (
 	"context"
 	"database/sql"
+	"errors"
 	"fmt"
+	"strings"
 	"time"
 
 	"sneak.berlin/go/vaultik/internal/types"
 )
 
+// SnapshotRepository provides access to the snapshots table and its
+// snapshot_files / snapshot_blobs association tables.
 type SnapshotRepository struct {
 	db *DB
 }
 
+// NewSnapshotRepository creates a SnapshotRepository backed by db.
 func NewSnapshotRepository(db *DB) *SnapshotRepository {
 	return &SnapshotRepository{db: db}
 }
 
-func (r *SnapshotRepository) Create(ctx context.Context, tx *sql.Tx, snapshot *Snapshot) error {
+// Create inserts a snapshot row, using tx when non-nil.
+func (r *SnapshotRepository) Create(
+	ctx context.Context, tx *sql.Tx, snapshot *Snapshot,
+) error {
 	query := `
-		INSERT INTO snapshots (id, hostname, vaultik_version, vaultik_git_revision, started_at, completed_at, 
-			file_count, chunk_count, blob_count, total_size, blob_size, blob_uncompressed_size, 
-			compression_ratio, compression_level, upload_bytes, upload_duration_ms)
+		INSERT INTO snapshots (id, hostname, vaultik_version,
+			vaultik_git_revision, started_at, completed_at,
+			file_count, chunk_count, blob_count, total_size, blob_size,
+			blob_uncompressed_size, compression_ratio, compression_level,
+			upload_bytes, upload_duration_ms)
 		VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
 	`
 
 	var completedAt *int64
+
 	if snapshot.CompletedAt != nil {
 		ts := snapshot.CompletedAt.Unix()
 		completedAt = &ts
 	}
 
+	args := []any{
+		snapshot.ID, snapshot.Hostname, snapshot.VaultikVersion,
+		snapshot.VaultikGitRevision, snapshot.StartedAt.Unix(),
+		completedAt, snapshot.FileCount, snapshot.ChunkCount,
+		snapshot.BlobCount, snapshot.TotalSize, snapshot.BlobSize,
+		snapshot.BlobUncompressedSize, snapshot.CompressionRatio,
+		snapshot.CompressionLevel, snapshot.UploadBytes,
+		snapshot.UploadDurationMs,
+	}
+
 	var err error
 	if tx != nil {
-		_, err = tx.ExecContext(ctx, query, snapshot.ID, snapshot.Hostname, snapshot.VaultikVersion, snapshot.VaultikGitRevision, snapshot.StartedAt.Unix(),
-			completedAt, snapshot.FileCount, snapshot.ChunkCount, snapshot.BlobCount, snapshot.TotalSize, snapshot.BlobSize, snapshot.BlobUncompressedSize,
-			snapshot.CompressionRatio, snapshot.CompressionLevel, snapshot.UploadBytes, snapshot.UploadDurationMs)
+		_, err = tx.ExecContext(ctx, query, args...)
 	} else {
-		_, err = r.db.ExecWithLog(ctx, query, snapshot.ID, snapshot.Hostname, snapshot.VaultikVersion, snapshot.VaultikGitRevision, snapshot.StartedAt.Unix(),
-			completedAt, snapshot.FileCount, snapshot.ChunkCount, snapshot.BlobCount, snapshot.TotalSize, snapshot.BlobSize, snapshot.BlobUncompressedSize,
-			snapshot.CompressionRatio, snapshot.CompressionLevel, snapshot.UploadBytes, snapshot.UploadDurationMs)
+		_, err = r.db.ExecWithLog(ctx, query, args...)
 	}
 
 	if err != nil {
@@ -49,7 +66,14 @@ func (r *SnapshotRepository) Create(ctx context.Context, tx *sql.Tx, snapshot *S
 	return nil
 }
 
-func (r *SnapshotRepository) UpdateCounts(ctx context.Context, tx *sql.Tx, snapshotID string, fileCount, chunkCount, blobCount, totalSize, blobSize int64) error {
+// UpdateCounts updates a snapshot's file/chunk/blob counters and sizes,
+// recomputing the compression ratio, using tx when non-nil.
+func (r *SnapshotRepository) UpdateCounts(
+	ctx context.Context,
+	tx *sql.Tx,
+	snapshotID string,
+	fileCount, chunkCount, blobCount, totalSize, blobSize int64,
+) error {
 	compressionRatio := 1.0
 	if totalSize > 0 {
 		compressionRatio = float64(blobSize) / float64(totalSize)
@@ -68,9 +92,13 @@ func (r *SnapshotRepository) UpdateCounts(ctx context.Context, tx *sql.Tx, snaps
 
 	var err error
 	if tx != nil {
-		_, err = tx.ExecContext(ctx, query, fileCount, chunkCount, blobCount, totalSize, blobSize, compressionRatio, snapshotID)
+		_, err = tx.ExecContext(ctx, query,
+			fileCount, chunkCount, blobCount, totalSize, blobSize,
+			compressionRatio, snapshotID)
 	} else {
-		_, err = r.db.ExecWithLog(ctx, query, fileCount, chunkCount, blobCount, totalSize, blobSize, compressionRatio, snapshotID)
+		_, err = r.db.ExecWithLog(ctx, query,
+			fileCount, chunkCount, blobCount, totalSize, blobSize,
+			compressionRatio, snapshotID)
 	}
 
 	if err != nil {
@@ -81,27 +109,19 @@ func (r *SnapshotRepository) UpdateCounts(ctx context.Context, tx *sql.Tx, snaps
 }
 
 // UpdateExtendedStats updates extended statistics for a snapshot
-func (r *SnapshotRepository) UpdateExtendedStats(ctx context.Context, tx *sql.Tx, snapshotID string, blobUncompressedSize int64, compressionLevel int, uploadDurationMs int64) error {
-	// Calculate compression ratio based on uncompressed vs compressed sizes
-	var compressionRatio float64
-	if blobUncompressedSize > 0 {
-		// Get current blob_size from DB to calculate ratio
-		var blobSize int64
-		queryGet := `SELECT blob_size FROM snapshots WHERE id = ?`
-		if tx != nil {
-			err := tx.QueryRowContext(ctx, queryGet, snapshotID).Scan(&blobSize)
+func (r *SnapshotRepository) UpdateExtendedStats(
+	ctx context.Context,
+	tx *sql.Tx,
+	snapshotID string,
+	blobUncompressedSize int64,
+	compressionLevel int,
+	uploadDurationMs int64,
+) error {
+	compressionRatio, err := r.extendedCompressionRatio(
+		ctx, tx, snapshotID, blobUncompressedSize,
+	)
 	if err != nil {
-				return fmt.Errorf("getting blob size: %w", err)
-			}
-		} else {
-			err := r.db.conn.QueryRowContext(ctx, queryGet, snapshotID).Scan(&blobSize)
-			if err != nil {
-				return fmt.Errorf("getting blob size: %w", err)
-			}
-		}
-		compressionRatio = float64(blobSize) / float64(blobUncompressedSize)
-	} else {
-		compressionRatio = 1.0
+		return err
 	}
 
 	query := `
@@ -114,20 +134,28 @@ func (r *SnapshotRepository) UpdateExtendedStats(ctx context.Context, tx *sql.Tx
 		WHERE id = ?
 	`
 
-	var err error
 	if tx != nil {
-		_, err = tx.ExecContext(ctx, query, blobUncompressedSize, compressionRatio, compressionLevel, uploadDurationMs, snapshotID)
+		_, err = tx.ExecContext(ctx, query,
+			blobUncompressedSize, compressionRatio, compressionLevel,
+			uploadDurationMs, snapshotID)
 	} else {
-		_, err = r.db.ExecWithLog(ctx, query, blobUncompressedSize, compressionRatio, compressionLevel, uploadDurationMs, snapshotID)
+		_, err = r.db.ExecWithLog(ctx, query,
+			blobUncompressedSize, compressionRatio, compressionLevel,
+			uploadDurationMs, snapshotID)
 	}
 
 	if err != nil {
 		return fmt.Errorf("updating extended stats: %w", err)
 	}
+
 	return nil
 }
 
-func (r *SnapshotRepository) GetByID(ctx context.Context, snapshotID string) (*Snapshot, error) {
+// GetByID returns the snapshot with the given ID, or nil if no such
+// snapshot exists.
+func (r *SnapshotRepository) GetByID(
+	ctx context.Context, snapshotID string,
+) (*Snapshot, error) {
 	query := `
 		SELECT id, hostname, vaultik_version, vaultik_git_revision, started_at, completed_at, 
 			file_count, chunk_count, blob_count, total_size, blob_size, blob_uncompressed_size,
@@ -136,9 +164,11 @@ func (r *SnapshotRepository) GetByID(ctx context.Context, snapshotID string) (*S
 		WHERE id = ?
 	`
 
-	var snapshot Snapshot
-	var startedAtUnix int64
-	var completedAtUnix *int64
+	var (
+		snapshot        Snapshot
+		startedAtUnix   int64
+		completedAtUnix *int64
+	)
 
 	err := r.db.conn.QueryRowContext(ctx, query, snapshotID).Scan(
 		&snapshot.ID,
@@ -159,9 +189,10 @@ func (r *SnapshotRepository) GetByID(ctx context.Context, snapshotID string) (*S
 		&snapshot.UploadDurationMs,
 	)
 
-	if err == sql.ErrNoRows {
-		return nil, nil
+	if errors.Is(err, sql.ErrNoRows) {
+		return nil, nil //nolint:nilnil // nil,nil signals not-found; callers check nil
 	}
+
 	if err != nil {
 		return nil, fmt.Errorf("querying snapshot: %w", err)
 	}
@@ -175,9 +206,14 @@ func (r *SnapshotRepository) GetByID(ctx context.Context, snapshotID string) (*S
 	return &snapshot, nil
 }
 
-func (r *SnapshotRepository) ListRecent(ctx context.Context, limit int) ([]*Snapshot, error) {
+// ListRecent returns up to limit snapshots, most recently started first.
+func (r *SnapshotRepository) ListRecent(
+	ctx context.Context, limit int,
+) ([]*Snapshot, error) {
 	query := `
-		SELECT id, hostname, vaultik_version, vaultik_git_revision, started_at, completed_at, file_count, chunk_count, blob_count, total_size, blob_size, compression_ratio
+		SELECT id, hostname, vaultik_version, vaultik_git_revision,
+			started_at, completed_at, file_count, chunk_count, blob_count,
+			total_size, blob_size, compression_ratio
 		FROM snapshots
 		ORDER BY started_at DESC
 		LIMIT ?
@@ -189,44 +225,13 @@ func (r *SnapshotRepository) ListRecent(ctx context.Context, limit int) ([]*Snap
 	}
 	defer CloseRows(rows)
 
-	var snapshots []*Snapshot
-	for rows.Next() {
-		var snapshot Snapshot
-		var startedAtUnix int64
-		var completedAtUnix *int64
-
-		err := rows.Scan(
-			&snapshot.ID,
-			&snapshot.Hostname,
-			&snapshot.VaultikVersion,
-			&snapshot.VaultikGitRevision,
-			&startedAtUnix,
-			&completedAtUnix,
-			&snapshot.FileCount,
-			&snapshot.ChunkCount,
-			&snapshot.BlobCount,
-			&snapshot.TotalSize,
-			&snapshot.BlobSize,
-			&snapshot.CompressionRatio,
-		)
-		if err != nil {
-			return nil, fmt.Errorf("scanning snapshot: %w", err)
-		}
-
-		snapshot.StartedAt = time.Unix(startedAtUnix, 0)
-		if completedAtUnix != nil {
-			t := time.Unix(*completedAtUnix, 0)
-			snapshot.CompletedAt = &t
-		}
-
-		snapshots = append(snapshots, &snapshot)
-	}
-
-	return snapshots, rows.Err()
+	return r.scanSnapshotRows(rows)
 }
 
 // MarkComplete marks a snapshot as completed with the current timestamp
-func (r *SnapshotRepository) MarkComplete(ctx context.Context, tx *sql.Tx, snapshotID string) error {
+func (r *SnapshotRepository) MarkComplete(
+	ctx context.Context, tx *sql.Tx, snapshotID string,
+) error {
 	query := `
 		UPDATE snapshots 
 		SET completed_at = ?
@@ -250,7 +255,9 @@ func (r *SnapshotRepository) MarkComplete(ctx context.Context, tx *sql.Tx, snaps
 }
 
 // AddFile adds a file to a snapshot
-func (r *SnapshotRepository) AddFile(ctx context.Context, tx *sql.Tx, snapshotID string, filePath string) error {
+func (r *SnapshotRepository) AddFile(
+	ctx context.Context, tx *sql.Tx, snapshotID string, filePath string,
+) error {
 	query := `
 		INSERT OR IGNORE INTO snapshot_files (snapshot_id, file_id)
 		SELECT ?, id FROM files WHERE path = ?
@@ -271,7 +278,9 @@ func (r *SnapshotRepository) AddFile(ctx context.Context, tx *sql.Tx, snapshotID
 }
 
 // AddFileByID adds a file to a snapshot by file ID
-func (r *SnapshotRepository) AddFileByID(ctx context.Context, tx *sql.Tx, snapshotID string, fileID types.FileID) error {
+func (r *SnapshotRepository) AddFileByID(
+	ctx context.Context, tx *sql.Tx, snapshotID string, fileID types.FileID,
+) error {
 	query := `
 		INSERT OR IGNORE INTO snapshot_files (snapshot_id, file_id)
 		VALUES (?, ?)
@@ -292,37 +301,49 @@ func (r *SnapshotRepository) AddFileByID(ctx context.Context, tx *sql.Tx, snapsh
 }
 
 // AddFilesByIDBatch adds multiple files to a snapshot in batched inserts
-func (r *SnapshotRepository) AddFilesByIDBatch(ctx context.Context, tx *sql.Tx, snapshotID string, fileIDs []types.FileID) error {
+func (r *SnapshotRepository) AddFilesByIDBatch(
+	ctx context.Context, tx *sql.Tx, snapshotID string, fileIDs []types.FileID,
+) error {
 	if len(fileIDs) == 0 {
 		return nil
 	}
 
-	// Each entry has 2 values, so batch at 400 to be safe
+	// Each snapshot_files row binds this many SQL variables.
+	const snapshotFileCols = 2
+
+	// Batch at 400 rows to be safe with SQLite's variable limit.
 	const batchSize = 400
 
 	for i := 0; i < len(fileIDs); i += batchSize {
-		end := i + batchSize
-		if end > len(fileIDs) {
-			end = len(fileIDs)
-		}
+		end := min(i+batchSize, len(fileIDs))
+
 		batch := fileIDs[i:end]
 
 		query := "INSERT OR IGNORE INTO snapshot_files (snapshot_id, file_id) VALUES "
-		args := make([]interface{}, 0, len(batch)*2)
+
+		args := make([]any, 0, len(batch)*snapshotFileCols)
+
+		var querySb312 strings.Builder
+
 		for j, fileID := range batch {
 			if j > 0 {
-				query += ", "
+				querySb312.WriteString(", ")
 			}
-			query += "(?, ?)"
+
+			querySb312.WriteString("(?, ?)")
+
 			args = append(args, snapshotID, fileID.String())
 		}
 
+		query += querySb312.String() //nolint:gosec // G202: appends "?" placeholders only
+
 		var err error
 		if tx != nil {
 			_, err = tx.ExecContext(ctx, query, args...)
 		} else {
 			_, err = r.db.ExecWithLog(ctx, query, args...)
 		}
+
 		if err != nil {
 			return fmt.Errorf("batch adding files to snapshot: %w", err)
 		}
@@ -341,7 +362,9 @@ func (r *SnapshotRepository) AddFilesByIDBatch(ctx context.Context, tx *sql.Tx,
 // Returns the number of rows inserted (i.e. blobs that were previously
 // referenced indirectly via file_chunks but not yet recorded in
 // snapshot_blobs for this snapshot).
-func (r *SnapshotRepository) PopulateReferencedBlobs(ctx context.Context, tx *sql.Tx, snapshotID string) (int64, error) {
+func (r *SnapshotRepository) PopulateReferencedBlobs(
+	ctx context.Context, tx *sql.Tx, snapshotID string,
+) (int64, error) {
 	query := `
 		INSERT OR IGNORE INTO snapshot_blobs (snapshot_id, blob_id, blob_hash)
 		SELECT DISTINCT ?, blobs.id, blobs.blob_hash
@@ -353,23 +376,33 @@ func (r *SnapshotRepository) PopulateReferencedBlobs(ctx context.Context, tx *sq
 		  AND blobs.blob_hash IS NOT NULL
 	`
 
-	var result sql.Result
-	var err error
+	var (
+		result sql.Result
+		err    error
+	)
 	if tx != nil {
 		result, err = tx.ExecContext(ctx, query, snapshotID, snapshotID)
 	} else {
 		result, err = r.db.ExecWithLog(ctx, query, snapshotID, snapshotID)
 	}
+
 	if err != nil {
 		return 0, fmt.Errorf("populating referenced blobs: %w", err)
 	}
 
 	n, _ := result.RowsAffected()
+
 	return n, nil
 }
 
 // AddBlob adds a blob to a snapshot
-func (r *SnapshotRepository) AddBlob(ctx context.Context, tx *sql.Tx, snapshotID string, blobID types.BlobID, blobHash types.BlobHash) error {
+func (r *SnapshotRepository) AddBlob(
+	ctx context.Context,
+	tx *sql.Tx,
+	snapshotID string,
+	blobID types.BlobID,
+	blobHash types.BlobHash,
+) error {
 	query := `
 		INSERT OR IGNORE INTO snapshot_blobs (snapshot_id, blob_id, blob_hash)
 		VALUES (?, ?, ?)
@@ -390,7 +423,9 @@ func (r *SnapshotRepository) AddBlob(ctx context.Context, tx *sql.Tx, snapshotID
 }
 
 // GetBlobHashes returns all blob hashes for a snapshot
-func (r *SnapshotRepository) GetBlobHashes(ctx context.Context, snapshotID string) ([]string, error) {
+func (r *SnapshotRepository) GetBlobHashes(
+	ctx context.Context, snapshotID string,
+) ([]string, error) {
 	query := `
 		SELECT sb.blob_hash 
 		FROM snapshot_blobs sb
@@ -405,19 +440,26 @@ func (r *SnapshotRepository) GetBlobHashes(ctx context.Context, snapshotID strin
 	defer CloseRows(rows)
 
 	var blobs []string
+
 	for rows.Next() {
 		var blobHash string
-		if err := rows.Scan(&blobHash); err != nil {
+
+		err := rows.Scan(&blobHash)
+		if err != nil {
 			return nil, fmt.Errorf("scanning blob hash: %w", err)
 		}
+
 		blobs = append(blobs, blobHash)
 	}
 
 	return blobs, rows.Err()
 }
 
-// GetSnapshotTotalCompressedSize returns the total compressed size of all blobs referenced by a snapshot
-func (r *SnapshotRepository) GetSnapshotTotalCompressedSize(ctx context.Context, snapshotID string) (int64, error) {
+// GetSnapshotTotalCompressedSize returns the total compressed size of all
+// blobs referenced by a snapshot.
+func (r *SnapshotRepository) GetSnapshotTotalCompressedSize(
+	ctx context.Context, snapshotID string,
+) (int64, error) {
 	query := `
 		SELECT COALESCE(SUM(b.compressed_size), 0)
 		FROM snapshot_blobs sb
@@ -426,6 +468,7 @@ func (r *SnapshotRepository) GetSnapshotTotalCompressedSize(ctx context.Context,
 	`
 
 	var totalSize int64
+
 	err := r.db.conn.QueryRowContext(ctx, query, snapshotID).Scan(&totalSize)
 	if err != nil {
 		return 0, fmt.Errorf("querying total compressed size: %w", err)
@@ -436,7 +479,9 @@ func (r *SnapshotRepository) GetSnapshotTotalCompressedSize(ctx context.Context,
 
 // GetSnapshotUncompressedChunkSize returns the sum of plaintext sizes of all unique
 // chunks referenced by a snapshot (via snapshot_files → file_chunks → chunks).
-func (r *SnapshotRepository) GetSnapshotUncompressedChunkSize(ctx context.Context, snapshotID string) (int64, error) {
+func (r *SnapshotRepository) GetSnapshotUncompressedChunkSize(
+	ctx context.Context, snapshotID string,
+) (int64, error) {
 	query := `
 		SELECT COALESCE(SUM(c.size), 0)
 		FROM (
@@ -449,6 +494,7 @@ func (r *SnapshotRepository) GetSnapshotUncompressedChunkSize(ctx context.Contex
 	`
 
 	var totalSize int64
+
 	err := r.db.conn.QueryRowContext(ctx, query, snapshotID).Scan(&totalSize)
 	if err != nil {
 		return 0, fmt.Errorf("querying uncompressed chunk size: %w", err)
@@ -461,7 +507,9 @@ func (r *SnapshotRepository) GetSnapshotUncompressedChunkSize(ctx context.Contex
 // referenced by this snapshot but not by any earlier completed snapshot known to
 // the local database. The result is the marginal uncompressed data this snapshot
 // added to the dedup pool — i.e., the delta from prior snapshots.
-func (r *SnapshotRepository) GetSnapshotNewChunkSize(ctx context.Context, snapshotID string) (int64, error) {
+func (r *SnapshotRepository) GetSnapshotNewChunkSize(
+	ctx context.Context, snapshotID string,
+) (int64, error) {
 	query := `
 		WITH this_snap_chunks AS (
 			SELECT DISTINCT fc.chunk_hash
@@ -485,7 +533,10 @@ func (r *SnapshotRepository) GetSnapshotNewChunkSize(ctx context.Context, snapsh
 	`
 
 	var totalSize int64
-	err := r.db.conn.QueryRowContext(ctx, query, snapshotID, snapshotID, snapshotID).Scan(&totalSize)
+
+	err := r.db.conn.QueryRowContext(
+		ctx, query, snapshotID, snapshotID, snapshotID,
+	).Scan(&totalSize)
 	if err != nil {
 		return 0, fmt.Errorf("querying new chunk size: %w", err)
 	}
@@ -494,9 +545,13 @@ func (r *SnapshotRepository) GetSnapshotNewChunkSize(ctx context.Context, snapsh
 }
 
 // GetIncompleteSnapshots returns all snapshots that haven't been completed
-func (r *SnapshotRepository) GetIncompleteSnapshots(ctx context.Context) ([]*Snapshot, error) {
+func (r *SnapshotRepository) GetIncompleteSnapshots(
+	ctx context.Context,
+) ([]*Snapshot, error) {
 	query := `
-		SELECT id, hostname, vaultik_version, vaultik_git_revision, started_at, completed_at, file_count, chunk_count, blob_count, total_size, blob_size, compression_ratio
+		SELECT id, hostname, vaultik_version, vaultik_git_revision,
+			started_at, completed_at, file_count, chunk_count, blob_count,
+			total_size, blob_size, compression_ratio
 		FROM snapshots
 		WHERE completed_at IS NULL
 		ORDER BY started_at DESC
@@ -508,46 +563,17 @@ func (r *SnapshotRepository) GetIncompleteSnapshots(ctx context.Context) ([]*Sna
 	}
 	defer CloseRows(rows)
 
-	var snapshots []*Snapshot
-	for rows.Next() {
-		var snapshot Snapshot
-		var startedAtUnix int64
-		var completedAtUnix *int64
-
-		err := rows.Scan(
-			&snapshot.ID,
-			&snapshot.Hostname,
-			&snapshot.VaultikVersion,
-			&snapshot.VaultikGitRevision,
-			&startedAtUnix,
-			&completedAtUnix,
-			&snapshot.FileCount,
-			&snapshot.ChunkCount,
-			&snapshot.BlobCount,
-			&snapshot.TotalSize,
-			&snapshot.BlobSize,
-			&snapshot.CompressionRatio,
-		)
-		if err != nil {
-			return nil, fmt.Errorf("scanning snapshot: %w", err)
-		}
-
-		snapshot.StartedAt = time.Unix(startedAtUnix, 0)
-		if completedAtUnix != nil {
-			t := time.Unix(*completedAtUnix, 0)
-			snapshot.CompletedAt = &t
-		}
-
-		snapshots = append(snapshots, &snapshot)
-	}
-
-	return snapshots, rows.Err()
+	return r.scanSnapshotRows(rows)
 }
 
 // GetIncompleteByHostname returns all incomplete snapshots for a specific hostname
-func (r *SnapshotRepository) GetIncompleteByHostname(ctx context.Context, hostname string) ([]*Snapshot, error) {
+func (r *SnapshotRepository) GetIncompleteByHostname(
+	ctx context.Context, hostname string,
+) ([]*Snapshot, error) {
 	query := `
-		SELECT id, hostname, vaultik_version, vaultik_git_revision, started_at, completed_at, file_count, chunk_count, blob_count, total_size, blob_size, compression_ratio
+		SELECT id, hostname, vaultik_version, vaultik_git_revision,
+			started_at, completed_at, file_count, chunk_count, blob_count,
+			total_size, blob_size, compression_ratio
 		FROM snapshots
 		WHERE completed_at IS NULL AND hostname = ?
 		ORDER BY started_at DESC
@@ -560,10 +586,13 @@ func (r *SnapshotRepository) GetIncompleteByHostname(ctx context.Context, hostna
 	defer CloseRows(rows)
 
 	var snapshots []*Snapshot
+
 	for rows.Next() {
-		var snapshot Snapshot
-		var startedAtUnix int64
-		var completedAtUnix *int64
+		var (
+			snapshot        Snapshot
+			startedAtUnix   int64
+			completedAtUnix *int64
+		)
 
 		err := rows.Scan(
 			&snapshot.ID,
@@ -608,7 +637,9 @@ func (r *SnapshotRepository) Delete(ctx context.Context, snapshotID string) erro
 }
 
 // DeleteSnapshotFiles removes all snapshot_files entries for a snapshot
-func (r *SnapshotRepository) DeleteSnapshotFiles(ctx context.Context, snapshotID string) error {
+func (r *SnapshotRepository) DeleteSnapshotFiles(
+	ctx context.Context, snapshotID string,
+) error {
 	query := `DELETE FROM snapshot_files WHERE snapshot_id = ?`
 
 	_, err := r.db.ExecWithLog(ctx, query, snapshotID)
@@ -620,7 +651,9 @@ func (r *SnapshotRepository) DeleteSnapshotFiles(ctx context.Context, snapshotID
 }
 
 // DeleteSnapshotBlobs removes all snapshot_blobs entries for a snapshot
-func (r *SnapshotRepository) DeleteSnapshotBlobs(ctx context.Context, snapshotID string) error {
+func (r *SnapshotRepository) DeleteSnapshotBlobs(
+	ctx context.Context, snapshotID string,
+) error {
 	query := `DELETE FROM snapshot_blobs WHERE snapshot_id = ?`
 
 	_, err := r.db.ExecWithLog(ctx, query, snapshotID)
@@ -632,7 +665,9 @@ func (r *SnapshotRepository) DeleteSnapshotBlobs(ctx context.Context, snapshotID
 }
 
 // DeleteSnapshotUploads removes all uploads entries for a snapshot
-func (r *SnapshotRepository) DeleteSnapshotUploads(ctx context.Context, snapshotID string) error {
+func (r *SnapshotRepository) DeleteSnapshotUploads(
+	ctx context.Context, snapshotID string,
+) error {
 	query := `DELETE FROM uploads WHERE snapshot_id = ?`
 
 	_, err := r.db.ExecWithLog(ctx, query, snapshotID)
@@ -642,3 +677,77 @@ func (r *SnapshotRepository) DeleteSnapshotUploads(ctx context.Context, snapshot
 
 	return nil
 }
+
+// extendedCompressionRatio computes the compression ratio for a snapshot
+// from its stored blob_size and the given uncompressed size. Returns 1.0
+// when the uncompressed size is zero.
+func (r *SnapshotRepository) extendedCompressionRatio(
+	ctx context.Context,
+	tx *sql.Tx,
+	snapshotID string,
+	blobUncompressedSize int64,
+) (float64, error) {
+	if blobUncompressedSize <= 0 {
+		return 1.0, nil
+	}
+
+	// Get current blob_size from DB to calculate ratio
+	var blobSize int64
+
+	queryGet := `SELECT blob_size FROM snapshots WHERE id = ?`
+
+	var err error
+	if tx != nil {
+		err = tx.QueryRowContext(ctx, queryGet, snapshotID).Scan(&blobSize)
+	} else {
+		err = r.db.conn.QueryRowContext(ctx, queryGet, snapshotID).Scan(&blobSize)
+	}
+
+	if err != nil {
+		return 0, fmt.Errorf("getting blob size: %w", err)
+	}
+
+	return float64(blobSize) / float64(blobUncompressedSize), nil
+}
+
+// scanSnapshotRows scans the standard snapshot column set from a rows
+// iterator into Snapshot records.
+func (r *SnapshotRepository) scanSnapshotRows(rows *sql.Rows) ([]*Snapshot, error) {
+	var snapshots []*Snapshot
+
+	for rows.Next() {
+		var (
+			snapshot        Snapshot
+			startedAtUnix   int64
+			completedAtUnix *int64
+		)
+
+		err := rows.Scan(
+			&snapshot.ID,
+			&snapshot.Hostname,
+			&snapshot.VaultikVersion,
+			&snapshot.VaultikGitRevision,
+			&startedAtUnix,
+			&completedAtUnix,
+			&snapshot.FileCount,
+			&snapshot.ChunkCount,
+			&snapshot.BlobCount,
+			&snapshot.TotalSize,
+			&snapshot.BlobSize,
+			&snapshot.CompressionRatio,
+		)
+		if err != nil {
+			return nil, fmt.Errorf("scanning snapshot: %w", err)
+		}
+
+		snapshot.StartedAt = time.Unix(startedAtUnix, 0)
+		if completedAtUnix != nil {
+			t := time.Unix(*completedAtUnix, 0)
+			snapshot.CompletedAt = &t
+		}
+
+		snapshots = append(snapshots, &snapshot)
+	}
+
+	return snapshots, rows.Err()
+}

internal/database/snapshots_test.go

@@ -1,4 +1,4 @@
-package database
+package database_test
 
 import (
 	"context"
@@ -7,6 +7,7 @@ import (
 	"testing"
 	"time"
 
+	"sneak.berlin/go/vaultik/internal/database"
 	"sneak.berlin/go/vaultik/internal/types"
 )
 
@@ -21,17 +22,19 @@ const (
 )
 
 func TestSnapshotRepository(t *testing.T) {
+	t.Parallel()
+
 	db, cleanup := setupTestDB(t)
 	defer cleanup()
 
 	ctx := context.Background()
-	repo := NewSnapshotRepository(db)
+	repo := database.NewSnapshotRepository(db)
 
 	// Test Create
-	snapshot := &Snapshot{
+	snapshot := &database.Snapshot{
 		ID:               "2024-01-01T12:00:00Z",
-		Hostname:         "test-host",
-		VaultikVersion:   "1.0.0",
+		Hostname:         testHostname,
+		VaultikVersion:   testVersion,
 		StartedAt:        time.Now().Truncate(time.Second),
 		CompletedAt:      nil,
 		FileCount:        100,
@@ -52,62 +55,118 @@ func TestSnapshotRepository(t *testing.T) {
 	if err != nil {
 		t.Fatalf("failed to get snapshot: %v", err)
 	}
+
 	if retrieved == nil {
 		t.Fatal("expected snapshot, got nil")
 	}
+
 	if retrieved.ID != snapshot.ID {
 		t.Errorf("ID mismatch: got %s, want %s", retrieved.ID, snapshot.ID)
 	}
+
 	if retrieved.Hostname != snapshot.Hostname {
-		t.Errorf("hostname mismatch: got %s, want %s", retrieved.Hostname, snapshot.Hostname)
+		t.Errorf("hostname mismatch: got %s, want %s",
+			retrieved.Hostname, snapshot.Hostname)
 	}
+
 	if retrieved.FileCount != snapshot.FileCount {
-		t.Errorf("file count mismatch: got %d, want %d", retrieved.FileCount, snapshot.FileCount)
+		t.Errorf("file count mismatch: got %d, want %d",
+			retrieved.FileCount, snapshot.FileCount)
+	}
+}
+
+func TestSnapshotRepositoryUpdateCounts(t *testing.T) {
+	t.Parallel()
+
+	db, cleanup := setupTestDB(t)
+	defer cleanup()
+
+	ctx := context.Background()
+	repo := database.NewSnapshotRepository(db)
+
+	snapshot := &database.Snapshot{
+		ID:               "2024-01-02T12:00:00Z",
+		Hostname:         testHostname,
+		VaultikVersion:   testVersion,
+		StartedAt:        time.Now().Truncate(time.Second),
+		CompletedAt:      nil,
+		FileCount:        100,
+		ChunkCount:       500,
+		BlobCount:        10,
+		TotalSize:        oneHundredMebibytes,
+		BlobSize:         fortyMebibytes,
+		CompressionRatio: compressionRatioPoint4,
+	}
+
+	err := repo.Create(ctx, nil, snapshot)
+	if err != nil {
+		t.Fatalf("failed to create snapshot: %v", err)
 	}
 
 	// Test UpdateCounts
-	err = repo.UpdateCounts(ctx, nil, snapshot.ID.String(), 200, 1000, 20, twoHundredMebibytes, sixtyMebibytes)
+	err = repo.UpdateCounts(ctx, nil, snapshot.ID.String(),
+		200, 1000, 20, twoHundredMebibytes, sixtyMebibytes)
 	if err != nil {
 		t.Fatalf("failed to update counts: %v", err)
 	}
 
-	retrieved, err = repo.GetByID(ctx, snapshot.ID.String())
+	retrieved, err := repo.GetByID(ctx, snapshot.ID.String())
 	if err != nil {
 		t.Fatalf("failed to get updated snapshot: %v", err)
 	}
+
 	if retrieved.FileCount != 200 {
 		t.Errorf("file count not updated: got %d, want %d", retrieved.FileCount, 200)
 	}
+
 	if retrieved.ChunkCount != 1000 {
-		t.Errorf("chunk count not updated: got %d, want %d", retrieved.ChunkCount, 1000)
+		t.Errorf("chunk count not updated: got %d, want %d",
+			retrieved.ChunkCount, 1000)
 	}
+
 	if retrieved.BlobCount != 20 {
 		t.Errorf("blob count not updated: got %d, want %d", retrieved.BlobCount, 20)
 	}
+
 	if retrieved.TotalSize != twoHundredMebibytes {
-		t.Errorf("total size not updated: got %d, want %d", retrieved.TotalSize, twoHundredMebibytes)
-	}
-	if retrieved.BlobSize != sixtyMebibytes {
-		t.Errorf("blob size not updated: got %d, want %d", retrieved.BlobSize, sixtyMebibytes)
-	}
-	expectedRatio := compressionRatioPoint3 // 0.3
-	if math.Abs(retrieved.CompressionRatio-expectedRatio) > 0.001 {
-		t.Errorf("compression ratio not updated: got %f, want %f", retrieved.CompressionRatio, expectedRatio)
+		t.Errorf("total size not updated: got %d, want %d",
+			retrieved.TotalSize, twoHundredMebibytes)
 	}
 
-	// Test ListRecent
-	// Add more snapshots
-	for i := 2; i <= 5; i++ {
-		s := &Snapshot{
+	if retrieved.BlobSize != sixtyMebibytes {
+		t.Errorf("blob size not updated: got %d, want %d",
+			retrieved.BlobSize, sixtyMebibytes)
+	}
+
+	expectedRatio := compressionRatioPoint3 // 0.3
+	if math.Abs(retrieved.CompressionRatio-expectedRatio) > 0.001 {
+		t.Errorf("compression ratio not updated: got %f, want %f",
+			retrieved.CompressionRatio, expectedRatio)
+	}
+}
+
+func TestSnapshotRepositoryListRecent(t *testing.T) {
+	t.Parallel()
+
+	db, cleanup := setupTestDB(t)
+	defer cleanup()
+
+	ctx := context.Background()
+	repo := database.NewSnapshotRepository(db)
+
+	// Add snapshots
+	for i := 1; i <= 5; i++ {
+		s := &database.Snapshot{
 			ID:             types.SnapshotID(fmt.Sprintf("2024-01-0%dT12:00:00Z", i)),
-			Hostname:       "test-host",
-			VaultikVersion: "1.0.0",
+			Hostname:       testHostname,
+			VaultikVersion: testVersion,
 			StartedAt:      time.Now().Add(time.Duration(i) * time.Hour).Truncate(time.Second),
 			CompletedAt:    nil,
 			FileCount:      int64(100 * i),
 			ChunkCount:     int64(500 * i),
 			BlobCount:      int64(10 * i),
 		}
+
 		err := repo.Create(ctx, nil, s)
 		if err != nil {
 			t.Fatalf("failed to create snapshot %d: %v", i, err)
@@ -119,12 +178,13 @@ func TestSnapshotRepository(t *testing.T) {
 	if err != nil {
 		t.Fatalf("failed to list recent snapshots: %v", err)
 	}
+
 	if len(recent) != 3 {
 		t.Errorf("expected 3 recent snapshots, got %d", len(recent))
 	}
 
 	// Verify order (most recent first)
-	for i := 0; i < len(recent)-1; i++ {
+	for i := range len(recent) - 1 {
 		if recent[i].StartedAt.Before(recent[i+1].StartedAt) {
 			t.Error("snapshots not in descending order")
 		}
@@ -132,23 +192,27 @@ func TestSnapshotRepository(t *testing.T) {
 }
 
 func TestSnapshotRepositoryNotFound(t *testing.T) {
+	t.Parallel()
+
 	db, cleanup := setupTestDB(t)
 	defer cleanup()
 
 	ctx := context.Background()
-	repo := NewSnapshotRepository(db)
+	repo := database.NewSnapshotRepository(db)
 
 	// Test GetByID with non-existent ID
 	snapshot, err := repo.GetByID(ctx, "nonexistent")
 	if err != nil {
 		t.Fatalf("unexpected error: %v", err)
 	}
+
 	if snapshot != nil {
 		t.Error("expected nil for non-existent snapshot")
 	}
 
 	// Test UpdateCounts on non-existent snapshot
-	err = repo.UpdateCounts(ctx, nil, "nonexistent", 100, 200, 10, oneHundredMebibytes, fortyMebibytes)
+	err = repo.UpdateCounts(ctx, nil, "nonexistent",
+		100, 200, 10, oneHundredMebibytes, fortyMebibytes)
 	if err != nil {
 		t.Fatalf("unexpected error: %v", err)
 	}
@@ -156,16 +220,18 @@ func TestSnapshotRepositoryNotFound(t *testing.T) {
 }
 
 func TestSnapshotRepositoryDuplicate(t *testing.T) {
+	t.Parallel()
+
 	db, cleanup := setupTestDB(t)
 	defer cleanup()
 
 	ctx := context.Background()
-	repo := NewSnapshotRepository(db)
+	repo := database.NewSnapshotRepository(db)
 
-	snapshot := &Snapshot{
+	snapshot := &database.Snapshot{
 		ID:             "2024-01-01T12:00:00Z",
-		Hostname:       "test-host",
-		VaultikVersion: "1.0.0",
+		Hostname:       testHostname,
+		VaultikVersion: testVersion,
 		StartedAt:      time.Now().Truncate(time.Second),
 		CompletedAt:    nil,
 		FileCount:      100,

internal/database/uploads.go

@@ -3,6 +3,7 @@ package database
 import (
 	"context"
 	"database/sql"
+	"errors"
 	"time"
 
 	"sneak.berlin/go/vaultik/internal/log"
@@ -28,7 +29,9 @@ func NewUploadRepository(conn *sql.DB) *UploadRepository {
 }
 
 // Create inserts a new upload record
-func (r *UploadRepository) Create(ctx context.Context, tx *sql.Tx, upload *Upload) error {
+func (r *UploadRepository) Create(
+	ctx context.Context, tx *sql.Tx, upload *Upload,
+) error {
 	query := `
 		INSERT INTO uploads (blob_hash, snapshot_id, uploaded_at, size, duration_ms)
 		VALUES (?, ?, ?, ?, ?)
@@ -36,16 +39,22 @@ func (r *UploadRepository) Create(ctx context.Context, tx *sql.Tx, upload *Uploa
 
 	var err error
 	if tx != nil {
-		_, err = tx.ExecContext(ctx, query, upload.BlobHash, upload.SnapshotID, upload.UploadedAt, upload.Size, upload.DurationMs)
+		_, err = tx.ExecContext(ctx, query,
+			upload.BlobHash, upload.SnapshotID, upload.UploadedAt,
+			upload.Size, upload.DurationMs)
 	} else {
-		_, err = r.conn.ExecContext(ctx, query, upload.BlobHash, upload.SnapshotID, upload.UploadedAt, upload.Size, upload.DurationMs)
+		_, err = r.conn.ExecContext(ctx, query,
+			upload.BlobHash, upload.SnapshotID, upload.UploadedAt,
+			upload.Size, upload.DurationMs)
 	}
 
 	return err
 }
 
 // GetByBlobHash retrieves an upload record by blob hash
-func (r *UploadRepository) GetByBlobHash(ctx context.Context, blobHash string) (*Upload, error) {
+func (r *UploadRepository) GetByBlobHash(
+	ctx context.Context, blobHash string,
+) (*Upload, error) {
 	query := `
 		SELECT blob_hash, uploaded_at, size, duration_ms
 		FROM uploads
@@ -53,6 +62,7 @@ func (r *UploadRepository) GetByBlobHash(ctx context.Context, blobHash string) (
 	`
 
 	var upload Upload
+
 	err := r.conn.QueryRowContext(ctx, query, blobHash).Scan(
 		&upload.BlobHash,
 		&upload.UploadedAt,
@@ -60,9 +70,10 @@ func (r *UploadRepository) GetByBlobHash(ctx context.Context, blobHash string) (
 		&upload.DurationMs,
 	)
 
-	if err == sql.ErrNoRows {
-		return nil, nil
+	if errors.Is(err, sql.ErrNoRows) {
+		return nil, nil //nolint:nilnil // nil,nil signals not-found; callers check nil
 	}
+
 	if err != nil {
 		return nil, err
 	}
@@ -71,7 +82,9 @@ func (r *UploadRepository) GetByBlobHash(ctx context.Context, blobHash string) (
 }
 
 // GetRecentUploads retrieves recent uploads ordered by upload time
-func (r *UploadRepository) GetRecentUploads(ctx context.Context, limit int) ([]*Upload, error) {
+func (r *UploadRepository) GetRecentUploads(
+	ctx context.Context, limit int,
+) ([]*Upload, error) {
 	query := `
 		SELECT blob_hash, uploaded_at, size, duration_ms
 		FROM uploads
@@ -84,17 +97,24 @@ func (r *UploadRepository) GetRecentUploads(ctx context.Context, limit int) ([]*
 		return nil, err
 	}
 	defer func() {
-		if err := rows.Close(); err != nil {
+		err := rows.Close()
+		if err != nil {
 			log.Error("failed to close rows", "error", err)
 		}
 	}()
 
 	var uploads []*Upload
+
 	for rows.Next() {
 		var upload Upload
-		if err := rows.Scan(&upload.BlobHash, &upload.UploadedAt, &upload.Size, &upload.DurationMs); err != nil {
+
+		err := rows.Scan(
+			&upload.BlobHash, &upload.UploadedAt, &upload.Size, &upload.DurationMs,
+		)
+		if err != nil {
 			return nil, err
 		}
+
 		uploads = append(uploads, &upload)
 	}
 
@@ -102,7 +122,9 @@ func (r *UploadRepository) GetRecentUploads(ctx context.Context, limit int) ([]*
 }
 
 // GetUploadStats returns aggregate statistics for uploads
-func (r *UploadRepository) GetUploadStats(ctx context.Context, since time.Time) (*UploadStats, error) {
+func (r *UploadRepository) GetUploadStats(
+	ctx context.Context, since time.Time,
+) (*UploadStats, error) {
 	query := `
 		SELECT
 			COUNT(*) as count,
@@ -115,6 +137,7 @@ func (r *UploadRepository) GetUploadStats(ctx context.Context, since time.Time)
 	`
 
 	var stats UploadStats
+
 	err := r.conn.QueryRowContext(ctx, query, since).Scan(
 		&stats.Count,
 		&stats.TotalSize,
@@ -136,12 +159,17 @@ type UploadStats struct {
 }
 
 // GetCountBySnapshot returns the count of uploads for a specific snapshot
-func (r *UploadRepository) GetCountBySnapshot(ctx context.Context, snapshotID string) (int64, error) {
+func (r *UploadRepository) GetCountBySnapshot(
+	ctx context.Context, snapshotID string,
+) (int64, error) {
 	query := `SELECT COUNT(*) FROM uploads WHERE snapshot_id = ?`
+
 	var count int64
+
 	err := r.conn.QueryRowContext(ctx, query, snapshotID).Scan(&count)
 	if err != nil {
 		return 0, err
 	}
+
 	return count, nil
 }

internal/globals/globals.go

@@ -1,3 +1,5 @@
+// Package globals holds application-wide metadata (name, version,
+// commit) that is populated at build time via linker flags.
 package globals
 
 import (
@@ -5,16 +7,16 @@ import (
 )
 
 // Appname is the application name, populated from main().
-var Appname string = "vaultik"
+var Appname = "vaultik" //nolint:gochecknoglobals // set via -ldflags at build time
 
 // Version is the application version, populated from main().
-var Version string = "dev"
+var Version = "dev" //nolint:gochecknoglobals // set via -ldflags at build time
 
 // Commit is the git commit hash, populated from main().
-var Commit string = "unknown"
+var Commit = "unknown" //nolint:gochecknoglobals // set via -ldflags at build time
 
 // CommitDate is the ISO-8601 date of the commit, populated from main().
-var CommitDate string = "unknown"
+var CommitDate = "unknown" //nolint:gochecknoglobals // set via -ldflags at build time
 
 // Author identifies the upstream author of vaultik.
 const Author = "Jeffrey Paul <sneak@sneak.berlin>"
@@ -34,7 +36,8 @@ type Globals struct {
 	StartTime  time.Time
 }
 
-// New creates and returns a new Globals instance initialized with the package-level variables.
+// New creates and returns a new Globals instance initialized with the
+// package-level variables.
 func New() (*Globals, error) {
 	return &Globals{
 		Appname:    Appname,
@@ -44,11 +47,15 @@ func New() (*Globals, error) {
 	}, nil
 }
 
+// shortCommitLen is the number of commit-hash characters ShortCommit keeps.
+const shortCommitLen = 12
+
 // ShortCommit returns the first 12 chars of the commit hash, or the
 // whole string if it's shorter (e.g. "unknown").
 func (g *Globals) ShortCommit() string {
-	if len(g.Commit) > 12 {
-		return g.Commit[:12]
+	if len(g.Commit) > shortCommitLen {
+		return g.Commit[:shortCommitLen]
 	}
+
 	return g.Commit
 }

internal/globals/globals_test.go

@@ -1,12 +1,16 @@
-package globals
+package globals_test
 
 import (
 	"testing"
+
+	"sneak.berlin/go/vaultik/internal/globals"
 )
 
 // TestGlobalsNew ensures the globals package initializes correctly
 func TestGlobalsNew(t *testing.T) {
-	g, err := New()
+	t.Parallel()
+
+	g, err := globals.New()
 	if err != nil {
 		t.Fatalf("Failed to create Globals: %v", err)
 	}

internal/log/log.go

@@ -1,3 +1,5 @@
+// Package log provides the application-wide structured logger: slog
+// with a colorized TTY handler on terminals and JSON output otherwise.
 package log
 
 import (
@@ -12,12 +14,12 @@ import (
 	"golang.org/x/term"
 )
 
-// LogLevel represents the logging level.
-type LogLevel int
+// Level represents the logging level.
+type Level int
 
 const (
 	// LevelFatal represents a fatal error level that will exit the program.
-	LevelFatal LogLevel = iota
+	LevelFatal Level = iota
 	// LevelError represents an error level.
 	LevelError
 	// LevelWarn represents a warning level.
@@ -38,6 +40,7 @@ type Config struct {
 	Quiet   bool
 }
 
+//nolint:gochecknoglobals // package-level logger is the package's purpose
 var logger *slog.Logger
 
 // Initialize sets up the global logger based on the provided configuration.
@@ -45,18 +48,19 @@ func Initialize(cfg Config) {
 	// Determine log level based on configuration
 	var level slog.Level
 
-	if cfg.Cron || cfg.Quiet {
+	switch {
+	case cfg.Cron || cfg.Quiet:
 		// In cron/quiet mode keep warnings and errors visible — the
 		// whole point of --cron is to stay silent only on total
 		// success, so that anything cron emails to root is genuinely
 		// "something went wrong, look at it." A backup with stuck
 		// permission errors or skipped files should NOT be silent.
 		level = slog.LevelWarn
-	} else if cfg.Debug || strings.Contains(os.Getenv("GODEBUG"), "vaultik") {
+	case cfg.Debug || strings.Contains(os.Getenv("GODEBUG"), "vaultik"):
 		level = slog.LevelDebug
-	} else if cfg.Verbose {
+	case cfg.Verbose:
 		level = slog.LevelInfo
-	} else {
+	default:
 		level = slog.LevelWarn
 	}
 
@@ -78,12 +82,17 @@ func Initialize(cfg Config) {
 	slog.SetDefault(logger)
 }
 
+// callerSkipFrames is the number of stack frames between runtime.Caller
+// and the code that invoked the package-level logging function.
+const callerSkipFrames = 2
+
 // getCaller returns the caller information as a string
-func getCaller(skip int) string {
-	_, file, line, ok := runtime.Caller(skip)
+func getCaller() string {
+	_, file, line, ok := runtime.Caller(callerSkipFrames)
 	if !ok {
 		return "unknown"
 	}
+
 	return fmt.Sprintf("%s:%d", filepath.Base(file), line)
 }
 
@@ -91,9 +100,10 @@ func getCaller(skip int) string {
 func Fatal(msg string, args ...any) {
 	if logger != nil {
 		// Add caller info to args
-		args = append(args, "caller", getCaller(2))
+		args = append(args, "caller", getCaller())
 		logger.Error(msg, args...)
 	}
+
 	os.Exit(1)
 }
 
@@ -105,7 +115,7 @@ func Fatalf(format string, args ...any) {
 // Error logs an error message.
 func Error(msg string, args ...any) {
 	if logger != nil {
-		args = append(args, "caller", getCaller(2))
+		args = append(args, "caller", getCaller())
 		logger.Error(msg, args...)
 	}
 }
@@ -118,7 +128,7 @@ func Errorf(format string, args ...any) {
 // Warn logs a warning message.
 func Warn(msg string, args ...any) {
 	if logger != nil {
-		args = append(args, "caller", getCaller(2))
+		args = append(args, "caller", getCaller())
 		logger.Warn(msg, args...)
 	}
 }
@@ -131,7 +141,7 @@ func Warnf(format string, args ...any) {
 // Notice logs a notice message (mapped to Info level).
 func Notice(msg string, args ...any) {
 	if logger != nil {
-		args = append(args, "caller", getCaller(2))
+		args = append(args, "caller", getCaller())
 		logger.Info(msg, args...)
 	}
 }
@@ -144,7 +154,7 @@ func Noticef(format string, args ...any) {
 // Info logs an informational message.
 func Info(msg string, args ...any) {
 	if logger != nil {
-		args = append(args, "caller", getCaller(2))
+		args = append(args, "caller", getCaller())
 		logger.Info(msg, args...)
 	}
 }
@@ -157,7 +167,7 @@ func Infof(format string, args ...any) {
 // Debug logs a debug message.
 func Debug(msg string, args ...any) {
 	if logger != nil {
-		args = append(args, "caller", getCaller(2))
+		args = append(args, "caller", getCaller())
 		logger.Debug(msg, args...)
 	}
 }
@@ -172,11 +182,12 @@ func With(args ...any) *slog.Logger {
 	if logger != nil {
 		return logger.With(args...)
 	}
+
 	return slog.Default()
 }
 
 // WithContext returns a logger with the provided context.
-func WithContext(ctx context.Context) *slog.Logger {
+func WithContext(_ context.Context) *slog.Logger {
 	return logger
 }
 

internal/log/module.go

@@ -5,6 +5,8 @@ import (
 )
 
 // Module exports logging functionality for dependency injection.
+//
+//nolint:gochecknoglobals // fx module definitions are package globals
 var Module = fx.Module("log",
 	fx.Invoke(func(cfg Config) {
 		Initialize(cfg)
@@ -12,12 +14,12 @@ var Module = fx.Module("log",
 )
 
 // New creates a new logger configuration from provided options.
-func New(opts LogOptions) Config {
+func New(opts Options) Config {
 	return Config(opts)
 }
 
-// LogOptions are provided by the CLI.
-type LogOptions struct {
+// Options are provided by the CLI.
+type Options struct {
 	Verbose bool
 	Debug   bool
 	Cron    bool

internal/log/tty_handler.go

@@ -33,6 +33,7 @@ func NewTTYHandler(out io.Writer, opts *slog.HandlerOptions) *TTYHandler {
 	if opts == nil {
 		opts = &slog.HandlerOptions{}
 	}
+
 	return &TTYHandler{
 		out:  out,
 		opts: *opts,
@@ -54,7 +55,9 @@ func (h *TTYHandler) Handle(_ context.Context, r slog.Record) error {
 
 	// Level and color
 	level := r.Level.String()
+
 	var levelColor string
+
 	switch r.Level {
 	case slog.LevelDebug:
 		levelColor = colorGray
@@ -91,38 +94,47 @@ func (h *TTYHandler) Handle(_ context.Context, r slog.Record) error {
 			if a.Key == "bytes" {
 				value = formatBytes(a.Value.Int64())
 			}
+		case slog.KindAny, slog.KindBool, slog.KindFloat64, slog.KindString,
+			slog.KindTime, slog.KindUint64, slog.KindGroup, slog.KindLogValuer:
+			// Plain string form above is already correct for these kinds.
+		default:
+			// Future kinds also use the plain string form.
 		}
 
 		_, _ = fmt.Fprintf(h.out, " %s%s%s=%s%s%s",
 			colorCyan, a.Key, colorReset,
 			colorBlue, value, colorReset)
+
 		return true
 	})
 
 	_, _ = fmt.Fprintln(h.out)
+
 	return nil
 }
 
 // WithAttrs returns a new handler with the given attributes.
-func (h *TTYHandler) WithAttrs(attrs []slog.Attr) slog.Handler {
+func (h *TTYHandler) WithAttrs(_ []slog.Attr) slog.Handler {
 	return h // Simplified for now
 }
 
 // WithGroup returns a new handler with the given group name.
-func (h *TTYHandler) WithGroup(name string) slog.Handler {
+func (h *TTYHandler) WithGroup(_ string) slog.Handler {
 	return h // Simplified for now
 }
 
 // formatDuration formats a duration in a human-readable way
 func formatDuration(d time.Duration) string {
-	if d < time.Millisecond {
+	switch {
+	case d < time.Millisecond:
 		return fmt.Sprintf("%dµs", d.Microseconds())
-	} else if d < time.Second {
+	case d < time.Second:
 		return fmt.Sprintf("%dms", d.Milliseconds())
-	} else if d < time.Minute {
+	case d < time.Minute:
 		return fmt.Sprintf("%.1fs", d.Seconds())
-	}
+	default:
 		return d.String()
+	}
 }
 
 // formatBytes formats bytes in a human-readable way
@@ -131,10 +143,12 @@ func formatBytes(b int64) string {
 	if b < unit {
 		return fmt.Sprintf("%d B", b)
 	}
+
 	div, exp := int64(unit), 0
 	for n := b / unit; n >= unit; n /= unit {
 		div *= unit
 		exp++
 	}
+
 	return fmt.Sprintf("%.1f %cB", float64(b)/float64(div), "KMGTPE"[exp])
 }

internal/models/models.go

@@ -1,3 +1,5 @@
+// Package models defines shared value types describing files, chunks,
+// blobs, and snapshots as they move through the backup pipeline.
 package models
 
 import (

internal/models/models_test.go

@@ -1,17 +1,21 @@
-package models
+package models_test
 
 import (
 	"testing"
 	"time"
+
+	"sneak.berlin/go/vaultik/internal/models"
 )
 
 // TestModelsCompilation ensures all model types can be instantiated
 func TestModelsCompilation(t *testing.T) {
+	t.Parallel()
+
 	// This test primarily serves as a compilation test
 	// to ensure all types are properly defined
 
 	// Test FileInfo
-	fi := &FileInfo{
+	fi := &models.FileInfo{
 		Path:  "/test/file.txt",
 		MTime: time.Now(),
 		Size:  1024,
@@ -21,7 +25,7 @@ func TestModelsCompilation(t *testing.T) {
 	}
 
 	// Test ChunkInfo
-	ci := &ChunkInfo{
+	ci := &models.ChunkInfo{
 		Hash:   "abc123",
 		Size:   512,
 		Offset: 0,
@@ -31,7 +35,7 @@ func TestModelsCompilation(t *testing.T) {
 	}
 
 	// Test BlobInfo
-	bi := &BlobInfo{
+	bi := &models.BlobInfo{
 		Hash:       "blob123",
 		CreatedAt:  time.Now(),
 		Size:       1024,
@@ -42,7 +46,7 @@ func TestModelsCompilation(t *testing.T) {
 	}
 
 	// Test Snapshot
-	s := &Snapshot{
+	s := &models.Snapshot{
 		ID:        "2024-01-01T00:00:00Z",
 		Hostname:  "test-host",
 		Version:   "1.0.0",

internal/pidlock/pidlock.go

@@ -21,6 +21,13 @@ type Lock struct {
 	path string
 }
 
+const (
+	// lockDirPerm is the mode for the lock directory (owner-only).
+	lockDirPerm = 0o700
+	// pidFilePerm is the mode for the PID file (owner-only).
+	pidFilePerm = 0o600
+)
+
 // Acquire attempts to acquire a PID lock in the specified directory.
 // If the lock file exists and the process is still running, it returns
 // ErrAlreadyRunning with details about the existing process.
@@ -28,7 +35,8 @@ type Lock struct {
 // a Lock that must be released with Release().
 func Acquire(lockDir string) (*Lock, error) {
 	// Ensure lock directory exists
-	if err := os.MkdirAll(lockDir, 0700); err != nil {
+	err := os.MkdirAll(lockDir, lockDirPerm)
+	if err != nil {
 		return nil, fmt.Errorf("creating lock directory: %w", err)
 	}
 
@@ -46,7 +54,9 @@ func Acquire(lockDir string) (*Lock, error) {
 
 	// Write our PID
 	pid := os.Getpid()
-	if err := os.WriteFile(lockPath, []byte(strconv.Itoa(pid)), 0600); err != nil {
+
+	err = os.WriteFile(lockPath, []byte(strconv.Itoa(pid)), pidFilePerm)
+	if err != nil {
 		return nil, fmt.Errorf("writing PID file: %w", err)
 	}
 
@@ -64,7 +74,7 @@ func (l *Lock) Release() error {
 	existingPID, err := readPIDFile(l.path)
 	if err != nil {
 		// File already gone or unreadable - that's fine
-		return nil
+		return nil //nolint:nilerr // unreadable lock file means nothing to release
 	}
 
 	if existingPID != os.Getpid() {
@@ -72,17 +82,19 @@ func (l *Lock) Release() error {
 		return nil
 	}
 
-	if err := os.Remove(l.path); err != nil && !os.IsNotExist(err) {
+	err = os.Remove(l.path)
+	if err != nil && !os.IsNotExist(err) {
 		return fmt.Errorf("removing PID file: %w", err)
 	}
 
 	l.path = "" // Prevent double-release
+
 	return nil
 }
 
 // readPIDFile reads and parses the PID from a lock file.
 func readPIDFile(path string) (int, error) {
-	data, err := os.ReadFile(path)
+	data, err := os.ReadFile(path) //nolint:gosec // G304: path is our own lock file
 	if err != nil {
 		return 0, err
 	}
@@ -104,5 +116,6 @@ func isProcessRunning(pid int) bool {
 
 	// On Unix, FindProcess always succeeds. We need to send signal 0 to check.
 	err = process.Signal(syscall.Signal(0))
+
 	return err == nil
 }

internal/pidlock/pidlock_test.go

@@ -1,4 +1,4 @@
-package pidlock
+package pidlock_test
 
 import (
 	"os"
@@ -8,18 +8,22 @@ import (
 
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
+	"sneak.berlin/go/vaultik/internal/pidlock"
 )
 
 func TestAcquireAndRelease(t *testing.T) {
+	t.Parallel()
+
 	tmpDir := t.TempDir()
 
 	// Acquire lock
-	lock, err := Acquire(tmpDir)
+	lock, err := pidlock.Acquire(tmpDir)
 	require.NoError(t, err)
 	require.NotNil(t, lock)
 
 	// Verify PID file exists with our PID
-	data, err := os.ReadFile(filepath.Join(tmpDir, "vaultik.pid"))
+	pidPath := filepath.Join(tmpDir, "vaultik.pid")
+	data, err := os.ReadFile(pidPath) //nolint:gosec // G304: test's own temp file
 	require.NoError(t, err)
 	pid, err := strconv.Atoi(string(data))
 	require.NoError(t, err)
@@ -30,26 +34,31 @@ func TestAcquireAndRelease(t *testing.T) {
 	require.NoError(t, err)
 
 	// Verify PID file is gone
-	_, err = os.Stat(filepath.Join(tmpDir, "vaultik.pid"))
+	_, err = os.Stat(pidPath)
 	assert.True(t, os.IsNotExist(err))
 }
 
 func TestAcquireBlocksSecondInstance(t *testing.T) {
+	t.Parallel()
+
 	tmpDir := t.TempDir()
 
 	// Acquire first lock
-	lock1, err := Acquire(tmpDir)
+	lock1, err := pidlock.Acquire(tmpDir)
 	require.NoError(t, err)
+
 	require.NotNil(t, lock1)
 	defer func() { _ = lock1.Release() }()
 
 	// Try to acquire second lock - should fail
-	lock2, err := Acquire(tmpDir)
-	assert.ErrorIs(t, err, ErrAlreadyRunning)
+	lock2, err := pidlock.Acquire(tmpDir)
+	require.ErrorIs(t, err, pidlock.ErrAlreadyRunning)
 	assert.Nil(t, lock2)
 }
 
 func TestAcquireWithStaleLock(t *testing.T) {
+	t.Parallel()
+
 	tmpDir := t.TempDir()
 
 	// Write a stale PID file (PID that doesn't exist)
@@ -59,13 +68,14 @@ func TestAcquireWithStaleLock(t *testing.T) {
 	require.NoError(t, err)
 
 	// Should be able to acquire lock (stale lock is cleaned up)
-	lock, err := Acquire(tmpDir)
+	lock, err := pidlock.Acquire(tmpDir)
 	require.NoError(t, err)
+
 	require.NotNil(t, lock)
 	defer func() { _ = lock.Release() }()
 
 	// Verify our PID is now in the file
-	data, err := os.ReadFile(pidPath)
+	data, err := os.ReadFile(pidPath) //nolint:gosec // G304: test's own temp file
 	require.NoError(t, err)
 	pid, err := strconv.Atoi(string(data))
 	require.NoError(t, err)
@@ -73,9 +83,11 @@ func TestAcquireWithStaleLock(t *testing.T) {
 }
 
 func TestReleaseIsIdempotent(t *testing.T) {
+	t.Parallel()
+
 	tmpDir := t.TempDir()
 
-	lock, err := Acquire(tmpDir)
+	lock, err := pidlock.Acquire(tmpDir)
 	require.NoError(t, err)
 
 	// Release multiple times - should not error
@@ -87,17 +99,23 @@ func TestReleaseIsIdempotent(t *testing.T) {
 }
 
 func TestReleaseNilLock(t *testing.T) {
-	var lock *Lock
+	t.Parallel()
+
+	var lock *pidlock.Lock
+
 	err := lock.Release()
-	assert.NoError(t, err)
+	require.NoError(t, err)
 }
 
 func TestAcquireCreatesDirectory(t *testing.T) {
+	t.Parallel()
+
 	tmpDir := t.TempDir()
 	nestedDir := filepath.Join(tmpDir, "nested", "dir")
 
-	lock, err := Acquire(nestedDir)
+	lock, err := pidlock.Acquire(nestedDir)
 	require.NoError(t, err)
+
 	require.NotNil(t, lock)
 	defer func() { _ = lock.Release() }()
 

internal/s3/client.go

@@ -1,3 +1,5 @@
+// Package s3 wraps the AWS S3 SDK with a simplified client for vaultik's
+// bucket-and-prefix scoped object operations.
 package s3
 
 import (
@@ -42,7 +44,7 @@ type Config struct {
 // Used to suppress SDK warnings about checksums.
 type nopLogger struct{}
 
-func (nopLogger) Logf(classification logging.Classification, format string, v ...interface{}) {}
+func (nopLogger) Logf(_ logging.Classification, _ string, _ ...any) {}
 
 // NewClient creates a new S3 client with the provided configuration.
 // It establishes a connection to the S3-compatible storage service and
@@ -92,6 +94,7 @@ func (c *Client) PutObject(ctx context.Context, key string, data io.Reader) erro
 		Key:    aws.String(fullKey),
 		Body:   data,
 	})
+
 	return err
 }
 
@@ -104,13 +107,18 @@ type ProgressCallback func(bytesUploaded int64) error
 // The size parameter must be the exact size of the data to upload.
 // The progress callback is called periodically with the number of bytes uploaded.
 // Returns an error if the upload fails.
-func (c *Client) PutObjectWithProgress(ctx context.Context, key string, data io.Reader, size int64, progress ProgressCallback) error {
+func (c *Client) PutObjectWithProgress(
+	ctx context.Context, key string, data io.Reader,
+	size int64, progress ProgressCallback,
+) error {
 	fullKey := c.prefix + key
 
+	// uploadPartSize is 10MB for better progress granularity.
+	const uploadPartSize = 10 * 1024 * 1024
+
 	// Create an uploader with the S3 client
 	uploader := manager.NewUploader(c.s3Client, func(u *manager.Uploader) {
-		// Set part size to 10MB for better progress granularity
-		u.PartSize = 10 * 1024 * 1024
+		u.PartSize = uploadPartSize
 	})
 
 	// Create a progress reader that tracks upload progress
@@ -137,6 +145,7 @@ func (c *Client) PutObjectWithProgress(ctx context.Context, key string, data io.
 // close the returned reader when done to avoid resource leaks.
 func (c *Client) GetObject(ctx context.Context, key string) (io.ReadCloser, error) {
 	fullKey := c.prefix + key
+
 	result, err := c.s3Client.GetObject(ctx, &s3.GetObjectInput{
 		Bucket: aws.String(c.bucket),
 		Key:    aws.String(fullKey),
@@ -144,6 +153,7 @@ func (c *Client) GetObject(ctx context.Context, key string) (io.ReadCloser, erro
 	if err != nil {
 		return nil, err
 	}
+
 	return result.Body, nil
 }
 
@@ -156,6 +166,7 @@ func (c *Client) DeleteObject(ctx context.Context, key string) error {
 		Bucket: aws.String(c.bucket),
 		Key:    aws.String(fullKey),
 	})
+
 	return err
 }
 
@@ -168,6 +179,7 @@ func (c *Client) ListObjects(ctx context.Context, prefix string) ([]string, erro
 	fullPrefix := c.prefix + prefix
 
 	var keys []string
+
 	paginator := s3.NewListObjectsV2Paginator(c.s3Client, &s3.ListObjectsV2Input{
 		Bucket: aws.String(c.bucket),
 		Prefix: aws.String(fullPrefix),
@@ -186,6 +198,7 @@ func (c *Client) ListObjects(ctx context.Context, prefix string) ([]string, erro
 				if len(key) > len(c.prefix) {
 					key = key[len(c.prefix):]
 				}
+
 				keys = append(keys, key)
 			}
 		}
@@ -200,18 +213,23 @@ func (c *Client) ListObjects(ctx context.Context, prefix string) ([]string, erro
 // Note: This method returns false for any error, not just "not found".
 func (c *Client) HeadObject(ctx context.Context, key string) (bool, error) {
 	fullKey := c.prefix + key
+
 	_, err := c.s3Client.HeadObject(ctx, &s3.HeadObjectInput{
 		Bucket: aws.String(c.bucket),
 		Key:    aws.String(fullKey),
 	})
 	if err != nil {
-		var notFound *s3types.NotFound
-		var noSuchKey *s3types.NoSuchKey
+		var (
+			notFound  *s3types.NotFound
+			noSuchKey *s3types.NoSuchKey
+		)
 		if errors.As(err, &notFound) || errors.As(err, &noSuchKey) {
 			return false, nil
 		}
+
 		return false, err
 	}
+
 	return true, nil
 }
 
@@ -230,7 +248,9 @@ type ObjectInfo struct {
 // listing is complete or an error occurs. If an error occurs, it will be
 // sent as the last item with the Err field set. The recursive parameter
 // is currently unused but reserved for future use.
-func (c *Client) ListObjectsStream(ctx context.Context, prefix string, recursive bool) <-chan ObjectInfo {
+func (c *Client) ListObjectsStream(
+	ctx context.Context, prefix string, _ bool,
+) <-chan ObjectInfo {
 	ch := make(chan ObjectInfo)
 
 	go func() {
@@ -247,6 +267,7 @@ func (c *Client) ListObjectsStream(ctx context.Context, prefix string, recursive
 			page, err := paginator.NextPage(ctx)
 			if err != nil {
 				ch <- ObjectInfo{Err: err}
+
 				return
 			}
 
@@ -257,6 +278,7 @@ func (c *Client) ListObjectsStream(ctx context.Context, prefix string, recursive
 					if len(key) > len(c.prefix) {
 						key = key[len(c.prefix):]
 					}
+
 					ch <- ObjectInfo{
 						Key:  key,
 						Size: *obj.Size,
@@ -275,6 +297,7 @@ func (c *Client) ListObjectsStream(ctx context.Context, prefix string, recursive
 // Returns an error if the object doesn't exist or if the operation fails.
 func (c *Client) StatObject(ctx context.Context, key string) (*ObjectInfo, error) {
 	fullKey := c.prefix + key
+
 	result, err := c.s3Client.HeadObject(ctx, &s3.HeadObjectInput{
 		Bucket: aws.String(c.bucket),
 		Key:    aws.String(fullKey),
@@ -313,6 +336,7 @@ func (c *Client) Endpoint() string {
 	if c.endpoint == "" {
 		return "s3.amazonaws.com"
 	}
+
 	return c.endpoint
 }
 
@@ -329,11 +353,14 @@ func (pr *progressReader) Read(p []byte) (int, error) {
 	n, err := pr.reader.Read(p)
 	if n > 0 {
 		atomic.AddInt64(&pr.read, int64(n))
+
 		if pr.callback != nil {
-			if callbackErr := pr.callback(atomic.LoadInt64(&pr.read)); callbackErr != nil {
+			callbackErr := pr.callback(atomic.LoadInt64(&pr.read))
+			if callbackErr != nil {
 				return n, callbackErr
 			}
 		}
 	}
+
 	return n, err
 }

internal/s3/client_test.go

@@ -9,10 +9,12 @@ import (
 	"sneak.berlin/go/vaultik/internal/s3"
 )
 
+//nolint:paralleltest // test servers share a fixed localhost port
 func TestClient(t *testing.T) {
 	ts := NewTestServer(t)
 	defer func() {
-		if err := ts.Cleanup(); err != nil {
+		err := ts.Cleanup()
+		if err != nil {
 			t.Errorf("cleanup failed: %v", err)
 		}
 	}()
@@ -32,10 +34,21 @@ func TestClient(t *testing.T) {
 		t.Fatalf("failed to create client: %v", err)
 	}
 
-	// Test PutObject
 	testKey := "foo/bar.txt"
 	testData := []byte("test data")
-	err = client.PutObject(ctx, testKey, bytes.NewReader(testData))
+
+	verifyPutGetHead(ctx, t, client, testKey, testData)
+	verifyListAndDelete(ctx, t, client, testKey)
+}
+
+// verifyPutGetHead uploads an object, reads it back, and checks existence.
+func verifyPutGetHead(
+	ctx context.Context, t *testing.T, client *s3.Client,
+	testKey string, testData []byte,
+) {
+	t.Helper()
+
+	err := client.PutObject(ctx, testKey, bytes.NewReader(testData))
 	if err != nil {
 		t.Fatalf("failed to put object: %v", err)
 	}
@@ -46,7 +59,8 @@ func TestClient(t *testing.T) {
 		t.Fatalf("failed to get object: %v", err)
 	}
 	defer func() {
-		if err := reader.Close(); err != nil {
+		err := reader.Close()
+		if err != nil {
 			t.Errorf("failed to close reader: %v", err)
 		}
 	}()
@@ -65,18 +79,28 @@ func TestClient(t *testing.T) {
 	if err != nil {
 		t.Fatalf("failed to head object: %v", err)
 	}
+
 	if !exists {
 		t.Error("expected object to exist")
 	}
+}
+
+// verifyListAndDelete lists the object's prefix, deletes it, and checks
+// it is gone.
+func verifyListAndDelete(
+	ctx context.Context, t *testing.T, client *s3.Client, testKey string,
+) {
+	t.Helper()
 
-	// Test ListObjects
 	keys, err := client.ListObjects(ctx, "foo/")
 	if err != nil {
 		t.Fatalf("failed to list objects: %v", err)
 	}
+
 	if len(keys) != 1 {
 		t.Errorf("expected 1 key, got %d", len(keys))
 	}
+
 	if keys[0] != testKey {
 		t.Errorf("unexpected key: got %s, want %s", keys[0], testKey)
 	}
@@ -88,10 +112,11 @@ func TestClient(t *testing.T) {
 	}
 
 	// Verify deletion
-	exists, err = client.HeadObject(ctx, testKey)
+	exists, err := client.HeadObject(ctx, testKey)
 	if err != nil {
 		t.Fatalf("failed to head object after deletion: %v", err)
 	}
+
 	if exists {
 		t.Error("expected object to not exist after deletion")
 	}

internal/s3/module.go

@@ -10,6 +10,8 @@ import (
 // Module exports S3 functionality as an fx module.
 // It provides automatic dependency injection for the S3 client,
 // configuring it based on the application's configuration settings.
+//
+//nolint:gochecknoglobals // fx module definitions are package globals
 var Module = fx.Module("s3",
 	fx.Provide(
 		provideClient,
@@ -32,7 +34,7 @@ func provideClient(lc fx.Lifecycle, cfg *config.Config) (*Client, error) {
 	}
 
 	lc.Append(fx.Hook{
-		OnStop: func(ctx context.Context) error {
+		OnStop: func(_ context.Context) error {
 			// S3 client doesn't need explicit cleanup
 			return nil
 		},

internal/s3/s3_test.go

@@ -3,10 +3,10 @@ package s3_test
 import (
 	"bytes"
 	"context"
+	"errors"
 	"fmt"
 	"io"
 	"net/http"
-	"os"
 	"path/filepath"
 	"testing"
 	"time"
@@ -37,13 +37,16 @@ type TestServer struct {
 	logBuf   *bytes.Buffer
 }
 
+// testServerReadHeaderTimeout bounds header reads on the in-process
+// test server (gosec G112).
+const testServerReadHeaderTimeout = 5 * time.Second
+
 // NewTestServer creates and starts a new test server
 func NewTestServer(t *testing.T) *TestServer {
+	t.Helper()
+
 	// Create temp directory for any file operations
-	tempDir, err := os.MkdirTemp("", "vaultik-s3-test-*")
-	if err != nil {
-		t.Fatalf("failed to create temp dir: %v", err)
-	}
+	tempDir := t.TempDir()
 
 	// Create in-memory backend
 	backend := s3mem.New()
@@ -53,11 +56,13 @@ func NewTestServer(t *testing.T) *TestServer {
 	server := &http.Server{
 		Addr:              "localhost:9999",
 		Handler:           faker.Server(),
+		ReadHeaderTimeout: testServerReadHeaderTimeout,
 	}
 
 	// Start server in background
 	go func() {
-		if err := server.ListenAndServe(); err != nil && err != http.ErrServerClosed {
+		err := server.ListenAndServe()
+		if err != nil && !errors.Is(err, http.ErrServerClosed) {
 			t.Logf("test server error: %v", err)
 		}
 	}()
@@ -69,6 +74,14 @@ func NewTestServer(t *testing.T) *TestServer {
 	logBuf := &bytes.Buffer{}
 
 	// Create S3 client with custom logger
+	logFn := func(classification logging.Classification, format string, v ...any) {
+		// Capture logs to buffer instead of stdout
+		fmt.Fprintf(logBuf, "SDK %s %s %s\n",
+			time.Now().Format("2006/01/02 15:04:05"),
+			string(classification),
+			fmt.Sprintf(format, v...))
+	}
+
 	cfg, err := config.LoadDefaultConfig(context.Background(),
 		config.WithRegion(testRegion),
 		config.WithCredentialsProvider(credentials.NewStaticCredentialsProvider(
@@ -76,14 +89,9 @@ func NewTestServer(t *testing.T) *TestServer {
 			testSecretKey,
 			"",
 		)),
-		config.WithClientLogMode(aws.LogRetries|aws.LogRequestWithBody|aws.LogResponseWithBody),
-		config.WithLogger(logging.LoggerFunc(func(classification logging.Classification, format string, v ...interface{}) {
-			// Capture logs to buffer instead of stdout
-			fmt.Fprintf(logBuf, "SDK %s %s %s\n",
-				time.Now().Format("2006/01/02 15:04:05"),
-				string(classification),
-				fmt.Sprintf(format, v...))
-		})),
+		config.WithClientLogMode(
+			aws.LogRetries|aws.LogRequestWithBody|aws.LogResponseWithBody),
+		config.WithLogger(logging.LoggerFunc(logFn)),
 	)
 	if err != nil {
 		t.Fatalf("failed to create AWS config: %v", err)
@@ -120,16 +128,13 @@ func NewTestServer(t *testing.T) *TestServer {
 	return ts
 }
 
-// Cleanup shuts down the server and removes temp directory
+// Cleanup shuts down the server. The temp directory is removed
+// automatically by t.TempDir.
 func (ts *TestServer) Cleanup() error {
 	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
 	defer cancel()
 
-	if err := ts.server.Shutdown(ctx); err != nil {
-		return err
-	}
-
-	return os.RemoveAll(ts.tempDir)
+	return ts.server.Shutdown(ctx)
 }
 
 // Client returns the S3 client configured for the test server
@@ -138,10 +143,13 @@ func (ts *TestServer) Client() *s3.Client {
 }
 
 // TestBasicS3Operations tests basic store and retrieve operations
+//
+//nolint:paralleltest // test servers share a fixed localhost port
 func TestBasicS3Operations(t *testing.T) {
 	ts := NewTestServer(t)
 	defer func() {
-		if err := ts.Cleanup(); err != nil {
+		err := ts.Cleanup()
+		if err != nil {
 			t.Errorf("cleanup failed: %v", err)
 		}
 	}()
@@ -172,7 +180,8 @@ func TestBasicS3Operations(t *testing.T) {
 		t.Fatalf("failed to get object: %v", err)
 	}
 	defer func() {
-		if err := result.Body.Close(); err != nil {
+		err := result.Body.Close()
+		if err != nil {
 			t.Errorf("failed to close body: %v", err)
 		}
 	}()
@@ -189,10 +198,13 @@ func TestBasicS3Operations(t *testing.T) {
 }
 
 // TestBlobOperations tests blob storage patterns for vaultik
+//
+//nolint:paralleltest // test servers share a fixed localhost port
 func TestBlobOperations(t *testing.T) {
 	ts := NewTestServer(t)
 	defer func() {
-		if err := ts.Cleanup(); err != nil {
+		err := ts.Cleanup()
+		if err != nil {
 			t.Errorf("cleanup failed: %v", err)
 		}
 	}()
@@ -252,10 +264,13 @@ func TestBlobOperations(t *testing.T) {
 }
 
 // TestMetadataOperations tests metadata storage patterns
+//
+//nolint:paralleltest // test servers share a fixed localhost port
 func TestMetadataOperations(t *testing.T) {
 	ts := NewTestServer(t)
 	defer func() {
-		if err := ts.Cleanup(); err != nil {
+		err := ts.Cleanup()
+		if err != nil {
 			t.Errorf("cleanup failed: %v", err)
 		}
 	}()
@@ -280,7 +295,8 @@ func TestMetadataOperations(t *testing.T) {
 
 	// Store manifest
 	manifestKey := filepath.Join("metadata", snapshotID+".manifest.json.zst")
-	manifestData := []byte(`{"snapshot_id":"2024-01-01T12:00:00Z","blob_hashes":["hash1","hash2"]}`)
+	manifestData := []byte(`{"snapshot_id":"2024-01-01T12:00:00Z",` +
+		`"blob_hashes":["hash1","hash2"]}`)
 
 	_, err = client.PutObject(ctx, &s3.PutObjectInput{
 		Bucket: aws.String(testBucket),

internal/snapshot/backup_test.go

@@ -1,9 +1,11 @@
-package snapshot
+package snapshot_test
 
 import (
 	"context"
 	"crypto/sha256"
 	"database/sql"
+	"encoding/hex"
+	"errors"
 	"fmt"
 	"io"
 	"io/fs"
@@ -17,6 +19,12 @@ import (
 	"sneak.berlin/go/vaultik/internal/types"
 )
 
+// errBlobNotFound is returned by the mock S3 client for unknown hashes.
+var errBlobNotFound = errors.New("blob not found")
+
+// testFile1Name is the shared fixture filename used across backup tests.
+const testFile1Name = "file1.txt"
+
 // MockS3Client is a mock implementation of S3 operations for testing
 type MockS3Client struct {
 	storage map[string][]byte
@@ -28,36 +36,149 @@ func NewMockS3Client() *MockS3Client {
 	}
 }
 
-func (m *MockS3Client) PutBlob(ctx context.Context, hash string, data []byte) error {
+func (m *MockS3Client) PutBlob(_ context.Context, hash string, data []byte) error {
 	m.storage[hash] = data
+
 	return nil
 }
 
-func (m *MockS3Client) GetBlob(ctx context.Context, hash string) ([]byte, error) {
+func (m *MockS3Client) GetBlob(_ context.Context, hash string) ([]byte, error) {
 	data, ok := m.storage[hash]
 	if !ok {
-		return nil, fmt.Errorf("blob not found: %s", hash)
+		return nil, fmt.Errorf("%w: %s", errBlobNotFound, hash)
 	}
+
 	return data, nil
 }
 
-func (m *MockS3Client) BlobExists(ctx context.Context, hash string) (bool, error) {
+func (m *MockS3Client) BlobExists(_ context.Context, hash string) (bool, error) {
 	_, ok := m.storage[hash]
+
 	return ok, nil
 }
 
-func (m *MockS3Client) CreateBucket(ctx context.Context, bucket string) error {
+func (m *MockS3Client) CreateBucket(_ context.Context, _ string) error {
 	return nil
 }
 
+// verifyBackupFiles checks the file records created by a backup against
+// the fixture filesystem.
+func verifyBackupFiles(
+	ctx context.Context,
+	t *testing.T,
+	repos *database.Repositories,
+	testFS fstest.MapFS,
+) {
+	t.Helper()
+
+	files, err := repos.Files.ListByPrefix(ctx, "")
+	if err != nil {
+		t.Fatalf("Failed to list files: %v", err)
+	}
+
+	expectedFiles := map[string]bool{
+		testFile1Name:           true,
+		"dir1/file2.txt":        true,
+		"dir1/subdir/file3.txt": true,
+		"largefile.bin":         true,
+	}
+
+	if len(files) != len(expectedFiles) {
+		t.Errorf("Expected %d files, got %d", len(expectedFiles), len(files))
+	}
+
+	for _, file := range files {
+		if !expectedFiles[file.Path.String()] {
+			t.Errorf("Unexpected file in database: %s", file.Path)
+		}
+
+		delete(expectedFiles, file.Path.String())
+
+		// Verify file metadata
+		fsFile := testFS[file.Path.String()]
+		if fsFile == nil {
+			t.Errorf("File %s not found in test filesystem", file.Path)
+
+			continue
+		}
+
+		if file.Size != int64(len(fsFile.Data)) {
+			t.Errorf("File %s: expected size %d, got %d",
+				file.Path, len(fsFile.Data), file.Size)
+		}
+
+		if file.Mode != uint32(fsFile.Mode) {
+			t.Errorf("File %s: expected mode %o, got %o",
+				file.Path, fsFile.Mode, file.Mode)
+		}
+	}
+
+	if len(expectedFiles) > 0 {
+		t.Errorf("Files not found in database: %v", expectedFiles)
+	}
+}
+
+// verifyBackupChunksAndBlobs checks that chunking produced the expected
+// records and every referenced blob exists in the mock S3 store.
+func verifyBackupChunksAndBlobs(
+	ctx context.Context,
+	t *testing.T,
+	repos *database.Repositories,
+	s3Client *MockS3Client,
+	snapshotID string,
+) {
+	t.Helper()
+
+	chunks, err := repos.Chunks.List(ctx)
+	if err != nil {
+		t.Fatalf("Failed to list chunks: %v", err)
+	}
+
+	if len(chunks) == 0 {
+		t.Error("No chunks found in database")
+	}
+
+	// The large file should create 10 chunks (10MB / 1MB chunk size)
+	// Plus the small files
+	minExpectedChunks := 10 + 3
+	if len(chunks) < minExpectedChunks {
+		t.Errorf("Expected at least %d chunks, got %d", minExpectedChunks, len(chunks))
+	}
+
+	// Verify at least one blob was created and uploaded
+	// We can't list blobs directly, but we can check via snapshot blobs
+	blobHashes, err := repos.Snapshots.GetBlobHashes(ctx, snapshotID)
+	if err != nil {
+		t.Fatalf("Failed to get blob hashes: %v", err)
+	}
+
+	if len(blobHashes) == 0 {
+		t.Error("Expected at least one blob to be created")
+	}
+
+	for _, blobHash := range blobHashes {
+		// Check blob exists in mock S3
+		exists, err := s3Client.BlobExists(ctx, blobHash)
+		if err != nil {
+			t.Errorf("Failed to check blob %s: %v", blobHash, err)
+		}
+
+		if !exists {
+			t.Errorf("Blob %s not found in S3", blobHash)
+		}
+	}
+}
+
 func TestBackupWithInMemoryFS(t *testing.T) {
+	t.Parallel()
+
 	// Create a temporary directory for the database
 	tempDir := t.TempDir()
 	dbPath := filepath.Join(tempDir, "test.db")
 
 	// Create test filesystem
 	testFS := fstest.MapFS{
-		"file1.txt": &fstest.MapFile{
+		testFile1Name: &fstest.MapFile{
 			Data:    []byte("Hello, World!"),
 			Mode:    0644,
 			ModTime: time.Now(),
@@ -81,12 +202,15 @@ func TestBackupWithInMemoryFS(t *testing.T) {
 
 	// Initialize the database
 	ctx := context.Background()
+
 	db, err := database.New(ctx, dbPath)
 	if err != nil {
 		t.Fatalf("Failed to create database: %v", err)
 	}
+
 	defer func() {
-		if err := db.Close(); err != nil {
+		err := db.Close()
+		if err != nil {
 			t.Logf("Failed to close database: %v", err)
 		}
 	}()
@@ -121,96 +245,21 @@ func TestBackupWithInMemoryFS(t *testing.T) {
 		t.Error("Expected snapshot to have files")
 	}
 
-	// Verify files in database
-	files, err := repos.Files.ListByPrefix(ctx, "")
-	if err != nil {
-		t.Fatalf("Failed to list files: %v", err)
-	}
-
-	expectedFiles := map[string]bool{
-		"file1.txt":             true,
-		"dir1/file2.txt":        true,
-		"dir1/subdir/file3.txt": true,
-		"largefile.bin":         true,
-	}
-
-	if len(files) != len(expectedFiles) {
-		t.Errorf("Expected %d files, got %d", len(expectedFiles), len(files))
-	}
-
-	for _, file := range files {
-		if !expectedFiles[file.Path.String()] {
-			t.Errorf("Unexpected file in database: %s", file.Path)
-		}
-		delete(expectedFiles, file.Path.String())
-
-		// Verify file metadata
-		fsFile := testFS[file.Path.String()]
-		if fsFile == nil {
-			t.Errorf("File %s not found in test filesystem", file.Path)
-			continue
-		}
-
-		if file.Size != int64(len(fsFile.Data)) {
-			t.Errorf("File %s: expected size %d, got %d", file.Path, len(fsFile.Data), file.Size)
-		}
-
-		if file.Mode != uint32(fsFile.Mode) {
-			t.Errorf("File %s: expected mode %o, got %o", file.Path, fsFile.Mode, file.Mode)
-		}
-	}
-
-	if len(expectedFiles) > 0 {
-		t.Errorf("Files not found in database: %v", expectedFiles)
-	}
-
-	// Verify chunks
-	chunks, err := repos.Chunks.List(ctx)
-	if err != nil {
-		t.Fatalf("Failed to list chunks: %v", err)
-	}
-
-	if len(chunks) == 0 {
-		t.Error("No chunks found in database")
-	}
-
-	// The large file should create 10 chunks (10MB / 1MB chunk size)
-	// Plus the small files
-	minExpectedChunks := 10 + 3
-	if len(chunks) < minExpectedChunks {
-		t.Errorf("Expected at least %d chunks, got %d", minExpectedChunks, len(chunks))
-	}
-
-	// Verify at least one blob was created and uploaded
-	// We can't list blobs directly, but we can check via snapshot blobs
-	blobHashes, err := repos.Snapshots.GetBlobHashes(ctx, snapshotID)
-	if err != nil {
-		t.Fatalf("Failed to get blob hashes: %v", err)
-	}
-	if len(blobHashes) == 0 {
-		t.Error("Expected at least one blob to be created")
-	}
-
-	for _, blobHash := range blobHashes {
-		// Check blob exists in mock S3
-		exists, err := s3Client.BlobExists(ctx, blobHash)
-		if err != nil {
-			t.Errorf("Failed to check blob %s: %v", blobHash, err)
-		}
-		if !exists {
-			t.Errorf("Blob %s not found in S3", blobHash)
-		}
-	}
+	// Verify files, chunks, and blob records
+	verifyBackupFiles(ctx, t, repos, testFS)
+	verifyBackupChunksAndBlobs(ctx, t, repos, s3Client, snapshotID)
 }
 
 func TestBackupDeduplication(t *testing.T) {
+	t.Parallel()
+
 	// Create a temporary directory for the database
 	tempDir := t.TempDir()
 	dbPath := filepath.Join(tempDir, "test.db")
 
 	// Create test filesystem with duplicate content
 	testFS := fstest.MapFS{
-		"file1.txt": &fstest.MapFile{
+		testFile1Name: &fstest.MapFile{
 			Data:    []byte("Duplicate content"),
 			Mode:    0644,
 			ModTime: time.Now(),
@@ -229,12 +278,15 @@ func TestBackupDeduplication(t *testing.T) {
 
 	// Initialize the database
 	ctx := context.Background()
+
 	db, err := database.New(ctx, dbPath)
 	if err != nil {
 		t.Fatalf("Failed to create database: %v", err)
 	}
+
 	defer func() {
-		if err := db.Close(); err != nil {
+		err := db.Close()
+		if err != nil {
 			t.Logf("Failed to close database: %v", err)
 		}
 	}()
@@ -275,7 +327,8 @@ func TestBackupDeduplication(t *testing.T) {
 
 		// The duplicate content chunk should be referenced by 2 files
 		if chunk.Size == int64(len("Duplicate content")) && len(files) != 2 {
-			t.Errorf("Expected duplicate chunk to be referenced by 2 files, got %d", len(files))
+			t.Errorf("Expected duplicate chunk to be referenced by 2 files, got %d",
+				len(files))
 		}
 	}
 }
@@ -289,8 +342,19 @@ type BackupEngine struct {
 	}
 }
 
+// backupCounters accumulates statistics across a test backup run.
+type backupCounters struct {
+	fileCount  int64
+	chunkCount int64
+	blobCount  int64
+	totalSize  int64
+	blobSize   int64
+}
+
 // Backup performs a backup of the given filesystem
-func (b *BackupEngine) Backup(ctx context.Context, fsys fs.FS, root string) (string, error) {
+func (b *BackupEngine) Backup(
+	ctx context.Context, fsys fs.FS, root string,
+) (string, error) {
 	// Create a new snapshot
 	hostname, _ := os.Hostname()
 	snapshotID := time.Now().Format(time.RFC3339)
@@ -310,8 +374,7 @@ func (b *BackupEngine) Backup(ctx context.Context, fsys fs.FS, root string) (str
 		return "", err
 	}
 
-	// Track counters
-	var fileCount, chunkCount, blobCount, totalSize, blobSize int64
+	counters := &backupCounters{}
 
 	// Track which chunks we've seen to handle deduplication
 	processedChunks := make(map[string]bool)
@@ -339,6 +402,40 @@ func (b *BackupEngine) Backup(ctx context.Context, fsys fs.FS, root string) (str
 			return nil
 		}
 
+		return b.backupOneFile(ctx, fsys, path, info, processedChunks, counters)
+	})
+	if err != nil {
+		return "", err
+	}
+
+	// After all files are processed, create blobs for new chunks
+	err = b.createBlobsForChunks(ctx, snapshotID, processedChunks, counters)
+	if err != nil {
+		return "", err
+	}
+
+	// Update snapshot with final counts
+	err = b.repos.WithTx(ctx, func(ctx context.Context, tx *sql.Tx) error {
+		return b.repos.Snapshots.UpdateCounts(ctx, tx, snapshotID,
+			counters.fileCount, counters.chunkCount, counters.blobCount,
+			counters.totalSize, counters.blobSize)
+	})
+	if err != nil {
+		return "", err
+	}
+
+	return snapshotID, nil
+}
+
+// backupOneFile records a single regular file and its chunks.
+func (b *BackupEngine) backupOneFile(
+	ctx context.Context,
+	fsys fs.FS,
+	path string,
+	info fs.FileInfo,
+	processedChunks map[string]bool,
+	counters *backupCounters,
+) error {
 	// Create file record in a short transaction
 	file := &database.File{
 		Path:  types.FilePath(path),
@@ -348,15 +445,16 @@ func (b *BackupEngine) Backup(ctx context.Context, fsys fs.FS, root string) (str
 		UID:   1000, // Default UID for test
 		GID:   1000, // Default GID for test
 	}
-		err = b.repos.WithTx(ctx, func(ctx context.Context, tx *sql.Tx) error {
+
+	err := b.repos.WithTx(ctx, func(ctx context.Context, tx *sql.Tx) error {
 		return b.repos.Files.Create(ctx, tx, file)
 	})
 	if err != nil {
 		return err
 	}
 
-		fileCount++
-		totalSize += info.Size()
+	counters.fileCount++
+	counters.totalSize += info.Size()
 
 	// Read and process file in chunks
 	f, err := fsys.Open(path)
@@ -364,7 +462,8 @@ func (b *BackupEngine) Backup(ctx context.Context, fsys fs.FS, root string) (str
 		return err
 	}
 	defer func() {
-			if err := f.Close(); err != nil {
+		err := f.Close()
+		if err != nil {
 			// Log but don't fail since we're already in an error path potentially
 			fmt.Fprintf(os.Stderr, "Failed to close file: %v\n", err)
 		}
@@ -376,56 +475,15 @@ func (b *BackupEngine) Backup(ctx context.Context, fsys fs.FS, root string) (str
 
 	for {
 		n, err := f.Read(buffer)
-			if err != nil && err != io.EOF {
+		if err != nil && !errors.Is(err, io.EOF) {
 			return err
 		}
+
 		if n == 0 {
 			break
 		}
 
-			chunkData := buffer[:n]
-			chunkHash := calculateHash(chunkData)
-
-			// Check if chunk already exists (outside of transaction)
-			existingChunk, _ := b.repos.Chunks.GetByHash(ctx, chunkHash)
-			if existingChunk == nil {
-				// Create new chunk in a short transaction
-				err = b.repos.WithTx(ctx, func(ctx context.Context, tx *sql.Tx) error {
-					chunk := &database.Chunk{
-						ChunkHash: types.ChunkHash(chunkHash),
-						Size:      int64(n),
-					}
-					return b.repos.Chunks.Create(ctx, tx, chunk)
-				})
-				if err != nil {
-					return err
-				}
-				processedChunks[chunkHash] = true
-			}
-
-			// Create file-chunk mapping in a short transaction
-			err = b.repos.WithTx(ctx, func(ctx context.Context, tx *sql.Tx) error {
-				fileChunk := &database.FileChunk{
-					FileID:    file.ID,
-					Idx:       chunkIndex,
-					ChunkHash: types.ChunkHash(chunkHash),
-				}
-				return b.repos.FileChunks.Create(ctx, tx, fileChunk)
-			})
-			if err != nil {
-				return err
-			}
-
-			// Create chunk-file mapping in a short transaction
-			err = b.repos.WithTx(ctx, func(ctx context.Context, tx *sql.Tx) error {
-				chunkFile := &database.ChunkFile{
-					ChunkHash:  types.ChunkHash(chunkHash),
-					FileID:     file.ID,
-					FileOffset: int64(chunkIndex * defaultChunkSize),
-					Length:     int64(n),
-				}
-				return b.repos.ChunkFiles.Create(ctx, tx, chunkFile)
-			})
+		err = b.recordChunk(ctx, file, chunkIndex, buffer[:n], processedChunks)
 		if err != nil {
 			return err
 		}
@@ -434,21 +492,80 @@ func (b *BackupEngine) Backup(ctx context.Context, fsys fs.FS, root string) (str
 	}
 
 	return nil
-	})
+}
 
-	if err != nil {
-		return "", err
+// recordChunk creates the chunk record (if new) and its file associations.
+func (b *BackupEngine) recordChunk(
+	ctx context.Context,
+	file *database.File,
+	chunkIndex int,
+	chunkData []byte,
+	processedChunks map[string]bool,
+) error {
+	chunkHash := calculateHash(chunkData)
+
+	// Check if chunk already exists (outside of transaction)
+	existingChunk, _ := b.repos.Chunks.GetByHash(ctx, chunkHash)
+	if existingChunk == nil {
+		// Create new chunk in a short transaction
+		err := b.repos.WithTx(ctx, func(ctx context.Context, tx *sql.Tx) error {
+			chunk := &database.Chunk{
+				ChunkHash: types.ChunkHash(chunkHash),
+				Size:      int64(len(chunkData)),
 			}
 
-	// After all files are processed, create blobs for new chunks
+			return b.repos.Chunks.Create(ctx, tx, chunk)
+		})
+		if err != nil {
+			return err
+		}
+
+		processedChunks[chunkHash] = true
+	}
+
+	// Create file-chunk mapping in a short transaction
+	err := b.repos.WithTx(ctx, func(ctx context.Context, tx *sql.Tx) error {
+		fileChunk := &database.FileChunk{
+			FileID:    file.ID,
+			Idx:       chunkIndex,
+			ChunkHash: types.ChunkHash(chunkHash),
+		}
+
+		return b.repos.FileChunks.Create(ctx, tx, fileChunk)
+	})
+	if err != nil {
+		return err
+	}
+
+	// Create chunk-file mapping in a short transaction
+	return b.repos.WithTx(ctx, func(ctx context.Context, tx *sql.Tx) error {
+		chunkFile := &database.ChunkFile{
+			ChunkHash:  types.ChunkHash(chunkHash),
+			FileID:     file.ID,
+			FileOffset: int64(chunkIndex * defaultChunkSize),
+			Length:     int64(len(chunkData)),
+		}
+
+		return b.repos.ChunkFiles.Create(ctx, tx, chunkFile)
+	})
+}
+
+// createBlobsForChunks uploads one blob per new chunk and records the blob
+// metadata and snapshot association.
+func (b *BackupEngine) createBlobsForChunks(
+	ctx context.Context,
+	snapshotID string,
+	processedChunks map[string]bool,
+	counters *backupCounters,
+) error {
 	for chunkHash := range processedChunks {
 		// Get chunk data (outside of transaction)
 		chunk, err := b.repos.Chunks.GetByHash(ctx, chunkHash)
 		if err != nil {
-			return "", err
+			return err
 		}
 
-		chunkCount++
+		counters.chunkCount++
 
 		// In a real system, blobs would contain multiple chunks and be encrypted
 		// For testing, we'll create a blob with a "blob-" prefix to differentiate
@@ -458,26 +575,29 @@ func (b *BackupEngine) Backup(ctx context.Context, fsys fs.FS, root string) (str
 		dummyData := []byte(chunkHash)
 
 		// Upload to S3 as a blob
-		if err := b.s3Client.PutBlob(ctx, blobHash, dummyData); err != nil {
-			return "", err
+		err = b.s3Client.PutBlob(ctx, blobHash, dummyData)
+		if err != nil {
+			return err
 		}
 
 		// Create blob entry in a short transaction
 		blobID := types.NewBlobID()
+
 		err = b.repos.WithTx(ctx, func(ctx context.Context, tx *sql.Tx) error {
 			blob := &database.Blob{
 				ID:        blobID,
 				Hash:      types.BlobHash(blobHash),
 				CreatedTS: time.Now(),
 			}
+
 			return b.repos.Blobs.Create(ctx, tx, blob)
 		})
 		if err != nil {
-			return "", err
+			return err
 		}
 
-		blobCount++
-		blobSize += chunk.Size
+		counters.blobCount++
+		counters.blobSize += chunk.Size
 
 		// Create blob-chunk mapping in a short transaction
 		err = b.repos.WithTx(ctx, func(ctx context.Context, tx *sql.Tx) error {
@@ -487,46 +607,41 @@ func (b *BackupEngine) Backup(ctx context.Context, fsys fs.FS, root string) (str
 				Offset:    0,
 				Length:    chunk.Size,
 			}
+
 			return b.repos.BlobChunks.Create(ctx, tx, blobChunk)
 		})
 		if err != nil {
-			return "", err
+			return err
 		}
 
 		// Add blob to snapshot in a short transaction
 		err = b.repos.WithTx(ctx, func(ctx context.Context, tx *sql.Tx) error {
-			return b.repos.Snapshots.AddBlob(ctx, tx, snapshotID, blobID, types.BlobHash(blobHash))
+			return b.repos.Snapshots.AddBlob(ctx, tx, snapshotID, blobID,
+				types.BlobHash(blobHash))
 		})
 		if err != nil {
-			return "", err
+			return err
 		}
 	}
 
-	// Update snapshot with final counts
-	err = b.repos.WithTx(ctx, func(ctx context.Context, tx *sql.Tx) error {
-		return b.repos.Snapshots.UpdateCounts(ctx, tx, snapshotID, fileCount, chunkCount, blobCount, totalSize, blobSize)
-	})
-
-	if err != nil {
-		return "", err
-	}
-
-	return snapshotID, nil
+	return nil
 }
 
 func calculateHash(data []byte) string {
 	h := sha256.New()
 	h.Write(data)
-	return fmt.Sprintf("%x", h.Sum(nil))
+
+	return hex.EncodeToString(h.Sum(nil))
 }
 
 func generateLargeFileContent(size int) []byte {
 	data := make([]byte, size)
 	// Fill with pattern that changes every chunk to avoid deduplication
-	for i := 0; i < size; i++ {
+	for i := range size {
 		chunkNum := i / defaultChunkSize
 		data[i] = byte((i + chunkNum) % 256)
 	}
+
 	return data
 }
 

internal/snapshot/exclude_test.go

@@ -10,16 +10,15 @@ import (
 	"github.com/spf13/afero"
 	"github.com/stretchr/testify/require"
 	"sneak.berlin/go/vaultik/internal/database"
-	"sneak.berlin/go/vaultik/internal/log"
 	"sneak.berlin/go/vaultik/internal/snapshot"
 	"sneak.berlin/go/vaultik/internal/types"
 )
 
-func setupExcludeTestFS(t *testing.T) afero.Fs {
+func setupExcludeTestFS(t *testing.T) *afero.MemMapFs {
 	t.Helper()
 
 	// Create in-memory filesystem
-	fs := afero.NewMemMapFs()
+	fs := &afero.MemMapFs{}
 
 	// Create test directory structure:
 	// /backup/
@@ -63,6 +62,7 @@ func setupExcludeTestFS(t *testing.T) afero.Fs {
 	}
 
 	testTime := time.Date(2024, 1, 1, 12, 0, 0, 0, time.UTC)
+
 	for path, content := range files {
 		dir := filepath.Dir(path)
 		err := fs.MkdirAll(dir, 0755)
@@ -76,12 +76,11 @@ func setupExcludeTestFS(t *testing.T) afero.Fs {
 	return fs
 }
 
-func createTestScanner(t *testing.T, fs afero.Fs, excludePatterns []string) (*snapshot.Scanner, *database.Repositories, func()) {
+func createTestScanner(
+	t *testing.T, fs afero.Fs, excludePatterns []string,
+) (*snapshot.Scanner, *database.Repositories, func()) {
 	t.Helper()
 
-	// Initialize logger
-	log.Initialize(log.Config{})
-
 	// Create test database
 	db, err := database.NewTestDB()
 	require.NoError(t, err)
@@ -94,7 +93,8 @@ func createTestScanner(t *testing.T, fs afero.Fs, excludePatterns []string) (*sn
 		Repositories:     repos,
 		MaxBlobSize:      1024 * 1024,
 		CompressionLevel: 3,
-		AgeRecipients:    []string{"age1ql3z7hjy54pw3hyww5ayyfg7zqgvc7w3j2elw8zmrj2kg5sfn9aqmcac8p"},
+		AgeRecipients: []string{
+			"age1ql3z7hjy54pw3hyww5ayyfg7zqgvc7w3j2elw8zmrj2kg5sfn9aqmcac8p"},
 		Exclude: excludePatterns,
 	})
 
@@ -105,13 +105,16 @@ func createTestScanner(t *testing.T, fs afero.Fs, excludePatterns []string) (*sn
 	return scanner, repos, cleanup
 }
 
-func createSnapshotRecord(t *testing.T, ctx context.Context, repos *database.Repositories, snapshotID string) {
+func createSnapshotRecord(
+	ctx context.Context, t *testing.T, repos *database.Repositories, snapshotID string,
+) {
 	t.Helper()
+
 	err := repos.WithTx(ctx, func(ctx context.Context, tx *sql.Tx) error {
 		snap := &database.Snapshot{
 			ID:               types.SnapshotID(snapshotID),
-			Hostname:         "test-host",
-			VaultikVersion:   "test",
+			Hostname:         testHost,
+			VaultikVersion:   testVersion,
 			StartedAt:        time.Now(),
 			CompletedAt:      nil,
 			FileCount:        0,
@@ -121,25 +124,31 @@ func createSnapshotRecord(t *testing.T, ctx context.Context, repos *database.Rep
 			BlobSize:         0,
 			CompressionRatio: 1.0,
 		}
+
 		return repos.Snapshots.Create(ctx, tx, snap)
 	})
 	require.NoError(t, err)
 }
 
 func TestExcludePatterns_ExcludeGitDirectory(t *testing.T) {
+	t.Parallel()
+
 	fs := setupExcludeTestFS(t)
+
 	scanner, repos, cleanup := createTestScanner(t, fs, []string{".git"})
 	defer cleanup()
+
 	require.NotNil(t, scanner)
 
 	ctx := context.Background()
-	createSnapshotRecord(t, ctx, repos, "test-snapshot")
+	createSnapshotRecord(ctx, t, repos, "test-snapshot")
 
 	result, err := scanner.Scan(ctx, "/backup", "test-snapshot")
 	require.NoError(t, err)
 
 	// Should have scanned files but NOT .git directory contents
-	// Expected: file1.txt, file2.log, src/main.go, src/test.go, node_modules/package/index.js,
+	// Expected: file1.txt, file2.log, src/main.go, src/test.go,
+	//           node_modules/package/index.js,
 	//           cache/temp.dat, build/output.bin, docs/readme.md, .DS_Store, thumbs.db,
 	//           src/.hidden, important.log.bak
 	// Excluded: .git/config, .git/objects/pack/data.pack
@@ -147,13 +156,17 @@ func TestExcludePatterns_ExcludeGitDirectory(t *testing.T) {
 }
 
 func TestExcludePatterns_ExcludeByExtension(t *testing.T) {
+	t.Parallel()
+
 	fs := setupExcludeTestFS(t)
+
 	scanner, repos, cleanup := createTestScanner(t, fs, []string{"*.log"})
 	defer cleanup()
+
 	require.NotNil(t, scanner)
 
 	ctx := context.Background()
-	createSnapshotRecord(t, ctx, repos, "test-snapshot")
+	createSnapshotRecord(ctx, t, repos, "test-snapshot")
 
 	result, err := scanner.Scan(ctx, "/backup", "test-snapshot")
 	require.NoError(t, err)
@@ -164,13 +177,17 @@ func TestExcludePatterns_ExcludeByExtension(t *testing.T) {
 }
 
 func TestExcludePatterns_ExcludeNodeModules(t *testing.T) {
+	t.Parallel()
+
 	fs := setupExcludeTestFS(t)
+
 	scanner, repos, cleanup := createTestScanner(t, fs, []string{"node_modules"})
 	defer cleanup()
+
 	require.NotNil(t, scanner)
 
 	ctx := context.Background()
-	createSnapshotRecord(t, ctx, repos, "test-snapshot")
+	createSnapshotRecord(ctx, t, repos, "test-snapshot")
 
 	result, err := scanner.Scan(ctx, "/backup", "test-snapshot")
 	require.NoError(t, err)
@@ -181,30 +198,41 @@ func TestExcludePatterns_ExcludeNodeModules(t *testing.T) {
 }
 
 func TestExcludePatterns_MultiplePatterns(t *testing.T) {
+	t.Parallel()
+
 	fs := setupExcludeTestFS(t)
-	scanner, repos, cleanup := createTestScanner(t, fs, []string{".git", "node_modules", "*.log", ".DS_Store", "thumbs.db", "cache", "build"})
+
+	scanner, repos, cleanup := createTestScanner(t, fs, []string{
+		".git", "node_modules", "*.log", ".DS_Store", "thumbs.db", "cache", "build"})
 	defer cleanup()
+
 	require.NotNil(t, scanner)
 
 	ctx := context.Background()
-	createSnapshotRecord(t, ctx, repos, "test-snapshot")
+	createSnapshotRecord(ctx, t, repos, "test-snapshot")
 
 	result, err := scanner.Scan(ctx, "/backup", "test-snapshot")
 	require.NoError(t, err)
 
-	// Should only have: file1.txt, src/main.go, src/test.go, docs/readme.md, src/.hidden, important.log.bak
-	// Excluded: .git/*, node_modules/*, *.log (file2.log), .DS_Store, thumbs.db, cache/*, build/*
+	// Should only have: file1.txt, src/main.go, src/test.go, docs/readme.md,
+	// src/.hidden, important.log.bak
+	// Excluded: .git/*, node_modules/*, *.log (file2.log), .DS_Store,
+	// thumbs.db, cache/*, build/*
 	require.Equal(t, 6, result.FilesScanned, "Should exclude multiple patterns")
 }
 
 func TestExcludePatterns_NoExclusions(t *testing.T) {
+	t.Parallel()
+
 	fs := setupExcludeTestFS(t)
+
 	scanner, repos, cleanup := createTestScanner(t, fs, []string{})
 	defer cleanup()
+
 	require.NotNil(t, scanner)
 
 	ctx := context.Background()
-	createSnapshotRecord(t, ctx, repos, "test-snapshot")
+	createSnapshotRecord(ctx, t, repos, "test-snapshot")
 
 	result, err := scanner.Scan(ctx, "/backup", "test-snapshot")
 	require.NoError(t, err)
@@ -214,30 +242,40 @@ func TestExcludePatterns_NoExclusions(t *testing.T) {
 }
 
 func TestExcludePatterns_ExcludeHiddenFiles(t *testing.T) {
+	t.Parallel()
+
 	fs := setupExcludeTestFS(t)
+
 	scanner, repos, cleanup := createTestScanner(t, fs, []string{".*"})
 	defer cleanup()
+
 	require.NotNil(t, scanner)
 
 	ctx := context.Background()
-	createSnapshotRecord(t, ctx, repos, "test-snapshot")
+	createSnapshotRecord(ctx, t, repos, "test-snapshot")
 
 	result, err := scanner.Scan(ctx, "/backup", "test-snapshot")
 	require.NoError(t, err)
 
 	// Should exclude: .git/*, .DS_Store, src/.hidden
-	// Total files: 14, excluded: 4 (.git/config, .git/objects/pack/data.pack, .DS_Store, src/.hidden)
-	require.Equal(t, 10, result.FilesScanned, "Should exclude hidden files and directories")
+	// Total files: 14, excluded: 4 (.git/config,
+	// .git/objects/pack/data.pack, .DS_Store, src/.hidden)
+	require.Equal(t, 10, result.FilesScanned,
+		"Should exclude hidden files and directories")
 }
 
 func TestExcludePatterns_DoubleStarGlob(t *testing.T) {
+	t.Parallel()
+
 	fs := setupExcludeTestFS(t)
+
 	scanner, repos, cleanup := createTestScanner(t, fs, []string{"**/*.pack"})
 	defer cleanup()
+
 	require.NotNil(t, scanner)
 
 	ctx := context.Background()
-	createSnapshotRecord(t, ctx, repos, "test-snapshot")
+	createSnapshotRecord(ctx, t, repos, "test-snapshot")
 
 	result, err := scanner.Scan(ctx, "/backup", "test-snapshot")
 	require.NoError(t, err)
@@ -248,13 +286,17 @@ func TestExcludePatterns_DoubleStarGlob(t *testing.T) {
 }
 
 func TestExcludePatterns_ExactFileName(t *testing.T) {
+	t.Parallel()
+
 	fs := setupExcludeTestFS(t)
+
 	scanner, repos, cleanup := createTestScanner(t, fs, []string{"thumbs.db", ".DS_Store"})
 	defer cleanup()
+
 	require.NotNil(t, scanner)
 
 	ctx := context.Background()
-	createSnapshotRecord(t, ctx, repos, "test-snapshot")
+	createSnapshotRecord(ctx, t, repos, "test-snapshot")
 
 	result, err := scanner.Scan(ctx, "/backup", "test-snapshot")
 	require.NoError(t, err)
@@ -265,14 +307,18 @@ func TestExcludePatterns_ExactFileName(t *testing.T) {
 }
 
 func TestExcludePatterns_CaseSensitive(t *testing.T) {
+	t.Parallel()
+
 	// Pattern matching should be case-sensitive
 	fs := setupExcludeTestFS(t)
+
 	scanner, repos, cleanup := createTestScanner(t, fs, []string{"THUMBS.DB"})
 	defer cleanup()
+
 	require.NotNil(t, scanner)
 
 	ctx := context.Background()
-	createSnapshotRecord(t, ctx, repos, "test-snapshot")
+	createSnapshotRecord(ctx, t, repos, "test-snapshot")
 
 	result, err := scanner.Scan(ctx, "/backup", "test-snapshot")
 	require.NoError(t, err)
@@ -283,32 +329,39 @@ func TestExcludePatterns_CaseSensitive(t *testing.T) {
 }
 
 func TestExcludePatterns_DirectoryWithTrailingSlash(t *testing.T) {
+	t.Parallel()
+
 	fs := setupExcludeTestFS(t)
 	// Some users might add trailing slashes to directory patterns
 	scanner, repos, cleanup := createTestScanner(t, fs, []string{"cache/", "build/"})
 	defer cleanup()
+
 	require.NotNil(t, scanner)
 
 	ctx := context.Background()
-	createSnapshotRecord(t, ctx, repos, "test-snapshot")
+	createSnapshotRecord(ctx, t, repos, "test-snapshot")
 
 	result, err := scanner.Scan(ctx, "/backup", "test-snapshot")
 	require.NoError(t, err)
 
 	// Should exclude cache/temp.dat and build/output.bin
 	// Total files: 14, excluded: 2
-	require.Equal(t, 12, result.FilesScanned, "Should handle directory patterns with trailing slashes")
+	require.Equal(t, 12, result.FilesScanned,
+		"Should handle directory patterns with trailing slashes")
 }
 
 func TestExcludePatterns_PatternInSubdirectory(t *testing.T) {
+	t.Parallel()
+
 	fs := setupExcludeTestFS(t)
 	// Exclude .hidden file specifically in src directory
 	scanner, repos, cleanup := createTestScanner(t, fs, []string{"src/.hidden"})
 	defer cleanup()
+
 	require.NotNil(t, scanner)
 
 	ctx := context.Background()
-	createSnapshotRecord(t, ctx, repos, "test-snapshot")
+	createSnapshotRecord(ctx, t, repos, "test-snapshot")
 
 	result, err := scanner.Scan(ctx, "/backup", "test-snapshot")
 	require.NoError(t, err)
@@ -327,13 +380,14 @@ func TestExcludePatterns_PatternInSubdirectory(t *testing.T) {
 //	    file.txt         (should be excluded with /projectname)
 //	  otherproject/
 //	    projectname/
-//	      file.txt       (should NOT be excluded with /projectname, only with projectname)
+//	      file.txt       (should NOT be excluded with /projectname,
+//	                      only with projectname)
 //	  src/
 //	    file.go
-func setupAnchoredTestFS(t *testing.T) afero.Fs {
+func setupAnchoredTestFS(t *testing.T) *afero.MemMapFs {
 	t.Helper()
 
-	fs := afero.NewMemMapFs()
+	fs := &afero.MemMapFs{}
 
 	files := map[string]string{
 		"/backup/projectname/file.txt":              "root project file",
@@ -343,6 +397,7 @@ func setupAnchoredTestFS(t *testing.T) afero.Fs {
 	}
 
 	testTime := time.Date(2024, 1, 1, 12, 0, 0, 0, time.UTC)
+
 	for path, content := range files {
 		dir := filepath.Dir(path)
 		err := fs.MkdirAll(dir, 0755)
@@ -357,14 +412,18 @@ func setupAnchoredTestFS(t *testing.T) afero.Fs {
 }
 
 func TestExcludePatterns_AnchoredPattern(t *testing.T) {
+	t.Parallel()
+
 	// Pattern starting with / should only match from root of source dir
 	fs := setupAnchoredTestFS(t)
+
 	scanner, repos, cleanup := createTestScanner(t, fs, []string{"/projectname"})
 	defer cleanup()
+
 	require.NotNil(t, scanner)
 
 	ctx := context.Background()
-	createSnapshotRecord(t, ctx, repos, "test-snapshot")
+	createSnapshotRecord(ctx, t, repos, "test-snapshot")
 
 	result, err := scanner.Scan(ctx, "/backup", "test-snapshot")
 	require.NoError(t, err)
@@ -372,18 +431,23 @@ func TestExcludePatterns_AnchoredPattern(t *testing.T) {
 	// /projectname should ONLY exclude /backup/projectname/file.txt (1 file)
 	// /backup/otherproject/projectname/file.txt should NOT be excluded
 	// Total files: 4, excluded: 1
-	require.Equal(t, 3, result.FilesScanned, "Anchored pattern /projectname should only match at root of source dir")
+	require.Equal(t, 3, result.FilesScanned,
+		"Anchored pattern /projectname should only match at root of source dir")
 }
 
 func TestExcludePatterns_UnanchoredPattern(t *testing.T) {
+	t.Parallel()
+
 	// Pattern without leading / should match anywhere in path
 	fs := setupAnchoredTestFS(t)
+
 	scanner, repos, cleanup := createTestScanner(t, fs, []string{"projectname"})
 	defer cleanup()
+
 	require.NotNil(t, scanner)
 
 	ctx := context.Background()
-	createSnapshotRecord(t, ctx, repos, "test-snapshot")
+	createSnapshotRecord(ctx, t, repos, "test-snapshot")
 
 	result, err := scanner.Scan(ctx, "/backup", "test-snapshot")
 	require.NoError(t, err)
@@ -392,18 +456,23 @@ func TestExcludePatterns_UnanchoredPattern(t *testing.T) {
 	// - /backup/projectname/file.txt
 	// - /backup/otherproject/projectname/file.txt
 	// Total files: 4, excluded: 2
-	require.Equal(t, 2, result.FilesScanned, "Unanchored pattern should match anywhere in path")
+	require.Equal(t, 2, result.FilesScanned,
+		"Unanchored pattern should match anywhere in path")
 }
 
 func TestExcludePatterns_AnchoredPatternWithGlob(t *testing.T) {
+	t.Parallel()
+
 	// Anchored pattern with glob
 	fs := setupAnchoredTestFS(t)
+
 	scanner, repos, cleanup := createTestScanner(t, fs, []string{"/src/*.go"})
 	defer cleanup()
+
 	require.NotNil(t, scanner)
 
 	ctx := context.Background()
-	createSnapshotRecord(t, ctx, repos, "test-snapshot")
+	createSnapshotRecord(ctx, t, repos, "test-snapshot")
 
 	result, err := scanner.Scan(ctx, "/backup", "test-snapshot")
 	require.NoError(t, err)
@@ -414,14 +483,18 @@ func TestExcludePatterns_AnchoredPatternWithGlob(t *testing.T) {
 }
 
 func TestExcludePatterns_AnchoredPatternFile(t *testing.T) {
+	t.Parallel()
+
 	// Anchored pattern for exact file at root
 	fs := setupAnchoredTestFS(t)
+
 	scanner, repos, cleanup := createTestScanner(t, fs, []string{"/file.txt"})
 	defer cleanup()
+
 	require.NotNil(t, scanner)
 
 	ctx := context.Background()
-	createSnapshotRecord(t, ctx, repos, "test-snapshot")
+	createSnapshotRecord(ctx, t, repos, "test-snapshot")
 
 	result, err := scanner.Scan(ctx, "/backup", "test-snapshot")
 	require.NoError(t, err)
@@ -429,18 +502,23 @@ func TestExcludePatterns_AnchoredPatternFile(t *testing.T) {
 	// /file.txt should ONLY exclude /backup/file.txt
 	// NOT /backup/projectname/file.txt or /backup/otherproject/projectname/file.txt
 	// Total files: 4, excluded: 1
-	require.Equal(t, 3, result.FilesScanned, "Anchored pattern for file should only match at root")
+	require.Equal(t, 3, result.FilesScanned,
+		"Anchored pattern for file should only match at root")
 }
 
 func TestExcludePatterns_UnanchoredPatternFile(t *testing.T) {
+	t.Parallel()
+
 	// Unanchored pattern for file should match anywhere
 	fs := setupAnchoredTestFS(t)
+
 	scanner, repos, cleanup := createTestScanner(t, fs, []string{"file.txt"})
 	defer cleanup()
+
 	require.NotNil(t, scanner)
 
 	ctx := context.Background()
-	createSnapshotRecord(t, ctx, repos, "test-snapshot")
+	createSnapshotRecord(ctx, t, repos, "test-snapshot")
 
 	result, err := scanner.Scan(ctx, "/backup", "test-snapshot")
 	require.NoError(t, err)
@@ -450,5 +528,6 @@ func TestExcludePatterns_UnanchoredPatternFile(t *testing.T) {
 	// - /backup/projectname/file.txt
 	// - /backup/otherproject/projectname/file.txt
 	// Total files: 4, excluded: 3
-	require.Equal(t, 1, result.FilesScanned, "Unanchored pattern for file should match anywhere")
+	require.Equal(t, 1, result.FilesScanned,
+		"Unanchored pattern for file should match anywhere")
 }

internal/snapshot/file_change_test.go

@@ -2,7 +2,6 @@ package snapshot_test
 
 import (
 	"context"
-	"database/sql"
 	"testing"
 	"time"
 
@@ -15,101 +14,20 @@ import (
 	"sneak.berlin/go/vaultik/internal/types"
 )
 
-// TestFileContentChange verifies that when a file's content changes,
-// the old chunks are properly disassociated
-func TestFileContentChange(t *testing.T) {
-	// Initialize logger for tests
-	log.Initialize(log.Config{})
-
-	// Create in-memory filesystem
-	fs := afero.NewMemMapFs()
-
-	// Create initial file
-	err := afero.WriteFile(fs, "/test.txt", []byte("Initial content"), 0644)
-	require.NoError(t, err)
-
-	// Create test database
-	db, err := database.NewTestDB()
-	require.NoError(t, err)
-	defer func() {
-		if err := db.Close(); err != nil {
-			t.Errorf("failed to close database: %v", err)
-		}
-	}()
-
-	repos := database.NewRepositories(db)
-
-	// Create scanner
-	scanner := snapshot.NewScanner(snapshot.ScannerConfig{
-		FS:               fs,
-		ChunkSize:        int64(1024 * 16), // 16KB chunks for testing
-		Repositories:     repos,
-		MaxBlobSize:      int64(1024 * 1024), // 1MB blobs
-		CompressionLevel: 3,
-		AgeRecipients:    []string{"age1ezrjmfpwsc95svdg0y54mums3zevgzu0x0ecq2f7tp8a05gl0sjq9q9wjg"}, // Test public key
-	})
-
-	// Create first snapshot
-	ctx := context.Background()
-	snapshotID1 := "snapshot1"
-	err = repos.WithTx(ctx, func(ctx context.Context, tx *sql.Tx) error {
-		snapshot := &database.Snapshot{
-			ID:             types.SnapshotID(snapshotID1),
-			Hostname:       "test-host",
-			VaultikVersion: "test",
-			StartedAt:      time.Now(),
-		}
-		return repos.Snapshots.Create(ctx, tx, snapshot)
-	})
-	require.NoError(t, err)
-
-	// First scan - should create chunks for initial content
-	result1, err := scanner.Scan(ctx, "/", snapshotID1)
-	require.NoError(t, err)
-	t.Logf("First scan: %d files scanned", result1.FilesScanned)
-
-	// Get file chunks from first scan
-	fileChunks1, err := repos.FileChunks.GetByPath(ctx, "/test.txt")
-	require.NoError(t, err)
-	assert.Len(t, fileChunks1, 1) // Small file = 1 chunk
-	oldChunkHash := fileChunks1[0].ChunkHash
-
-	// Get chunk files from first scan
-	chunkFiles1, err := repos.ChunkFiles.GetByFilePath(ctx, "/test.txt")
-	require.NoError(t, err)
-	assert.Len(t, chunkFiles1, 1)
-
-	// Modify the file
-	time.Sleep(10 * time.Millisecond) // Ensure mtime changes
-	err = afero.WriteFile(fs, "/test.txt", []byte("Modified content with different data"), 0644)
-	require.NoError(t, err)
-
-	// Create second snapshot
-	snapshotID2 := "snapshot2"
-	err = repos.WithTx(ctx, func(ctx context.Context, tx *sql.Tx) error {
-		snapshot := &database.Snapshot{
-			ID:             types.SnapshotID(snapshotID2),
-			Hostname:       "test-host",
-			VaultikVersion: "test",
-			StartedAt:      time.Now(),
-		}
-		return repos.Snapshots.Create(ctx, tx, snapshot)
-	})
-	require.NoError(t, err)
-
-	// Second scan - should create new chunks and remove old associations
-	result2, err := scanner.Scan(ctx, "/", snapshotID2)
-	require.NoError(t, err)
-	t.Logf("Second scan: %d files scanned", result2.FilesScanned)
-
-	// Get file chunks from second scan
-	fileChunks2, err := repos.FileChunks.GetByPath(ctx, "/test.txt")
-	require.NoError(t, err)
-	assert.Len(t, fileChunks2, 1) // Still 1 chunk but different hash
-	newChunkHash := fileChunks2[0].ChunkHash
+// verifyChunkChange checks that after a content change the file references
+// the new chunk, the old chunk still exists, and the old chunk no longer
+// maps to the modified file.
+func verifyChunkChange(
+	ctx context.Context,
+	t *testing.T,
+	repos *database.Repositories,
+	oldChunkHash, newChunkHash types.ChunkHash,
+) {
+	t.Helper()
 
 	// Verify the chunk hashes are different
-	assert.NotEqual(t, oldChunkHash, newChunkHash, "Chunk hash should change when content changes")
+	assert.NotEqual(t, oldChunkHash, newChunkHash,
+		"Chunk hash should change when content changes")
 
 	// Get chunk files from second scan
 	chunkFiles2, err := repos.ChunkFiles.GetByFilePath(ctx, "/test.txt")
@@ -130,17 +48,103 @@ func TestFileContentChange(t *testing.T) {
 	// Verify that chunk_files for old chunk no longer references this file
 	oldChunkFiles, err := repos.ChunkFiles.GetByChunkHash(ctx, oldChunkHash)
 	require.NoError(t, err)
+
 	for _, cf := range oldChunkFiles {
 		file, err := repos.Files.GetByID(ctx, cf.FileID)
 		require.NoError(t, err)
-		assert.NotEqual(t, "/data/test.txt", file.Path, "Old chunk should not be associated with the modified file")
+		assert.NotEqual(t, "/data/test.txt", file.Path,
+			"Old chunk should not be associated with the modified file")
 	}
 }
 
+// TestFileContentChange verifies that when a file's content changes,
+// the old chunks are properly disassociated
+func TestFileContentChange(t *testing.T) {
+	// Initialize logger for tests
+	log.Initialize(log.Config{})
+	t.Parallel()
+
+	// Create in-memory filesystem
+	fs := afero.NewMemMapFs()
+
+	// Create initial file
+	err := afero.WriteFile(fs, "/test.txt", []byte("Initial content"), 0644)
+	require.NoError(t, err)
+
+	// Create test database
+	db, err := database.NewTestDB()
+
+	require.NoError(t, err)
+	defer func() {
+		err := db.Close()
+		if err != nil {
+			t.Errorf("failed to close database: %v", err)
+		}
+	}()
+
+	repos := database.NewRepositories(db)
+
+	// Create scanner
+	scanner := snapshot.NewScanner(snapshot.ScannerConfig{
+		FS:               fs,
+		ChunkSize:        int64(1024 * 16), // 16KB chunks for testing
+		Repositories:     repos,
+		MaxBlobSize:      int64(1024 * 1024), // 1MB blobs
+		CompressionLevel: 3,
+		AgeRecipients:    []string{testAgePublicKey},
+	})
+
+	// Create first snapshot
+	ctx := context.Background()
+	snapshotID1 := "snapshot1"
+	createSnapshotRecord(ctx, t, repos, snapshotID1)
+
+	// First scan - should create chunks for initial content
+	result1, err := scanner.Scan(ctx, "/", snapshotID1)
+	require.NoError(t, err)
+	t.Logf("First scan: %d files scanned", result1.FilesScanned)
+
+	// Get file chunks from first scan
+	fileChunks1, err := repos.FileChunks.GetByPath(ctx, "/test.txt")
+	require.NoError(t, err)
+	assert.Len(t, fileChunks1, 1) // Small file = 1 chunk
+	oldChunkHash := fileChunks1[0].ChunkHash
+
+	// Get chunk files from first scan
+	chunkFiles1, err := repos.ChunkFiles.GetByFilePath(ctx, "/test.txt")
+	require.NoError(t, err)
+	assert.Len(t, chunkFiles1, 1)
+
+	// Modify the file
+	time.Sleep(10 * time.Millisecond) // Ensure mtime changes
+
+	err = afero.WriteFile(fs, "/test.txt",
+		[]byte("Modified content with different data"), 0644)
+	require.NoError(t, err)
+
+	// Create second snapshot
+	snapshotID2 := "snapshot2"
+	createSnapshotRecord(ctx, t, repos, snapshotID2)
+
+	// Second scan - should create new chunks and remove old associations
+	result2, err := scanner.Scan(ctx, "/", snapshotID2)
+	require.NoError(t, err)
+	t.Logf("Second scan: %d files scanned", result2.FilesScanned)
+
+	// Get file chunks from second scan
+	fileChunks2, err := repos.FileChunks.GetByPath(ctx, "/test.txt")
+	require.NoError(t, err)
+	assert.Len(t, fileChunks2, 1) // Still 1 chunk but different hash
+	newChunkHash := fileChunks2[0].ChunkHash
+
+	verifyChunkChange(ctx, t, repos, oldChunkHash, newChunkHash)
+}
+
 // TestMultipleFileChanges verifies handling of multiple file changes in one scan
 func TestMultipleFileChanges(t *testing.T) {
 	// Initialize logger for tests
 	log.Initialize(log.Config{})
+	t.Parallel()
 
 	// Create in-memory filesystem
 	fs := afero.NewMemMapFs()
@@ -159,9 +163,11 @@ func TestMultipleFileChanges(t *testing.T) {
 
 	// Create test database
 	db, err := database.NewTestDB()
+
 	require.NoError(t, err)
 	defer func() {
-		if err := db.Close(); err != nil {
+		err := db.Close()
+		if err != nil {
 			t.Errorf("failed to close database: %v", err)
 		}
 	}()
@@ -175,22 +181,13 @@ func TestMultipleFileChanges(t *testing.T) {
 		Repositories:     repos,
 		MaxBlobSize:      int64(1024 * 1024), // 1MB blobs
 		CompressionLevel: 3,
-		AgeRecipients:    []string{"age1ezrjmfpwsc95svdg0y54mums3zevgzu0x0ecq2f7tp8a05gl0sjq9q9wjg"}, // Test public key
+		AgeRecipients:    []string{testAgePublicKey},
 	})
 
 	// Create first snapshot
 	ctx := context.Background()
 	snapshotID1 := "snapshot1"
-	err = repos.WithTx(ctx, func(ctx context.Context, tx *sql.Tx) error {
-		snapshot := &database.Snapshot{
-			ID:             types.SnapshotID(snapshotID1),
-			Hostname:       "test-host",
-			VaultikVersion: "test",
-			StartedAt:      time.Now(),
-		}
-		return repos.Snapshots.Create(ctx, tx, snapshot)
-	})
-	require.NoError(t, err)
+	createSnapshotRecord(ctx, t, repos, snapshotID1)
 
 	// First scan
 	result1, err := scanner.Scan(ctx, "/", snapshotID1)
@@ -200,6 +197,7 @@ func TestMultipleFileChanges(t *testing.T) {
 
 	// Modify two files
 	time.Sleep(10 * time.Millisecond) // Ensure mtime changes
+
 	err = afero.WriteFile(fs, "/file1.txt", []byte("Modified content 1"), 0644)
 	require.NoError(t, err)
 	err = afero.WriteFile(fs, "/file3.txt", []byte("Modified content 3"), 0644)
@@ -207,16 +205,7 @@ func TestMultipleFileChanges(t *testing.T) {
 
 	// Create second snapshot
 	snapshotID2 := "snapshot2"
-	err = repos.WithTx(ctx, func(ctx context.Context, tx *sql.Tx) error {
-		snapshot := &database.Snapshot{
-			ID:             types.SnapshotID(snapshotID2),
-			Hostname:       "test-host",
-			VaultikVersion: "test",
-			StartedAt:      time.Now(),
-		}
-		return repos.Snapshots.Create(ctx, tx, snapshot)
-	})
-	require.NoError(t, err)
+	createSnapshotRecord(ctx, t, repos, snapshotID2)
 
 	// Second scan
 	result2, err := scanner.Scan(ctx, "/", snapshotID2)
@@ -229,10 +218,12 @@ func TestMultipleFileChanges(t *testing.T) {
 	for path := range files {
 		fileChunks, err := repos.FileChunks.GetByPath(ctx, path)
 		require.NoError(t, err)
-		assert.Len(t, fileChunks, 1, "File %s should have exactly 1 chunk association", path)
+		assert.Len(t, fileChunks, 1,
+			"File %s should have exactly 1 chunk association", path)
 
 		chunkFiles, err := repos.ChunkFiles.GetByFilePath(ctx, path)
 		require.NoError(t, err)
-		assert.Len(t, chunkFiles, 1, "File %s should have exactly 1 chunk-file association", path)
+		assert.Len(t, chunkFiles, 1,
+			"File %s should have exactly 1 chunk-file association", path)
 	}
 }

internal/snapshot/manifest.go

@@ -10,6 +10,8 @@ import (
 )
 
 // Manifest represents the structure of a snapshot's blob manifest
+//
+//nolint:tagliatelle // snake_case is the established on-disk manifest format
 type Manifest struct {
 	SnapshotID          string     `json:"snapshot_id"`
 	Timestamp           string     `json:"timestamp"`
@@ -19,6 +21,8 @@ type Manifest struct {
 }
 
 // BlobInfo represents information about a single blob in the manifest
+//
+//nolint:tagliatelle // snake_case is the established on-disk manifest format
 type BlobInfo struct {
 	Hash           string `json:"hash"`
 	CompressedSize int64  `json:"compressed_size"`
@@ -35,7 +39,9 @@ func DecodeManifest(r io.Reader) (*Manifest, error) {
 
 	// Decode JSON manifest
 	var manifest Manifest
-	if err := json.NewDecoder(zr).Decode(&manifest); err != nil {
+
+	err = json.NewDecoder(zr).Decode(&manifest)
+	if err != nil {
 		return nil, fmt.Errorf("decoding manifest: %w", err)
 	}
 
@@ -52,17 +58,22 @@ func EncodeManifest(manifest *Manifest, compressionLevel int) ([]byte, error) {
 
 	// Compress using zstd
 	var compressedBuf bytes.Buffer
-	writer, err := zstd.NewWriter(&compressedBuf, zstd.WithEncoderLevel(zstd.EncoderLevelFromZstd(compressionLevel)))
+
+	writer, err := zstd.NewWriter(&compressedBuf,
+		zstd.WithEncoderLevel(zstd.EncoderLevelFromZstd(compressionLevel)))
 	if err != nil {
 		return nil, fmt.Errorf("creating zstd writer: %w", err)
 	}
 
-	if _, err := writer.Write(jsonData); err != nil {
+	_, err = writer.Write(jsonData)
+	if err != nil {
 		_ = writer.Close()
+
 		return nil, fmt.Errorf("writing compressed data: %w", err)
 	}
 
-	if err := writer.Close(); err != nil {
+	err = writer.Close()
+	if err != nil {
 		return nil, fmt.Errorf("closing zstd writer: %w", err)
 	}
 

internal/snapshot/module.go

@@ -21,6 +21,8 @@ type ScannerParams struct {
 // Module exports backup functionality as an fx module.
 // It provides a ScannerFactory that can create Scanner instances
 // with custom parameters while sharing common dependencies.
+//
+//nolint:gochecknoglobals // fx module definitions are conventionally globals
 var Module = fx.Module("backup",
 	fx.Provide(
 		provideScannerFactory,
@@ -31,7 +33,9 @@ var Module = fx.Module("backup",
 // ScannerFactory creates scanners with custom parameters
 type ScannerFactory func(params ScannerParams) *Scanner
 
-func provideScannerFactory(cfg *config.Config, repos *database.Repositories, storer storage.Storer) ScannerFactory {
+func provideScannerFactory(
+	cfg *config.Config, repos *database.Repositories, storer storage.Storer,
+) ScannerFactory {
 	return func(params ScannerParams) *Scanner {
 		// Use provided excludes, or fall back to global config excludes
 		excludes := params.Exclude

internal/snapshot/permission_error_test.go

@@ -1,3 +1,4 @@
+//nolint:testpackage // needs access to unexported wrapPermissionError
 package snapshot
 
 import (
@@ -9,10 +10,15 @@ import (
 	"testing"
 )
 
+// errDiskOnFire is a non-permission sentinel used to verify pass-through.
+var errDiskOnFire = errors.New("disk on fire")
+
 func TestWrapPermissionError(t *testing.T) {
+	t.Parallel()
+
 	// Non-permission errors pass through unchanged.
-	plain := errors.New("disk on fire")
-	if got := wrapPermissionError("/some/path", plain); got != plain {
+	got := wrapPermissionError("/some/path", errDiskOnFire)
+	if !errors.Is(got, errDiskOnFire) {
 		t.Errorf("non-permission error should pass through, got %v", got)
 	}
 
@@ -23,20 +29,23 @@ func TestWrapPermissionError(t *testing.T) {
 	if !errors.Is(wrapped, os.ErrPermission) {
 		t.Error("wrapped error should still match os.ErrPermission")
 	}
+
 	if !strings.Contains(wrapped.Error(), "/Users/u/Library/Calendars") {
 		t.Error("wrapped error should name the offending path")
 	}
 
 	if runtime.GOOS == "darwin" {
 		if !strings.Contains(wrapped.Error(), "Full Disk Access") {
-			t.Errorf("macOS permission error should mention Full Disk Access:\n%s", wrapped.Error())
+			t.Errorf("macOS permission error should mention Full Disk Access:\n%s",
+				wrapped.Error())
 		}
+
 		if !strings.Contains(wrapped.Error(), "System Settings") {
-			t.Errorf("macOS permission error should point at System Settings:\n%s", wrapped.Error())
-		}
-	} else {
-		if !strings.Contains(wrapped.Error(), "--skip-errors") {
-			t.Errorf("non-macOS permission error should mention --skip-errors:\n%s", wrapped.Error())
+			t.Errorf("macOS permission error should point at System Settings:\n%s",
+				wrapped.Error())
 		}
+	} else if !strings.Contains(wrapped.Error(), "--skip-errors") {
+		t.Errorf("non-macOS permission error should mention --skip-errors:\n%s",
+			wrapped.Error())
 	}
 }

internal/snapshot/progress.go

@@ -19,14 +19,41 @@ const (
 	// These updates show current progress, ETA, and the file being processed.
 	SummaryInterval = 10 * time.Second
 
-	// DetailInterval defines how often multi-line detailed status reports are printed.
-	// These reports include comprehensive statistics about files, chunks, blobs, and uploads.
+	// DetailInterval defines how often multi-line detailed status reports are
+	// printed. These reports include comprehensive statistics about files,
+	// chunks, blobs, and uploads.
 	DetailInterval = 60 * time.Second
 
 	// UploadProgressInterval defines how often upload progress messages are logged.
 	UploadProgressInterval = 15 * time.Second
 )
 
+const (
+	// bitsPerByte converts byte counts to bit counts for speed display.
+	bitsPerByte = 8
+
+	// percentScale converts a ratio to a percentage.
+	percentScale = 100
+
+	// currentFileMaxLen is the display width used for current-file paths.
+	currentFileMaxLen = 40
+
+	// secondsPerMinute and minutesPerHour are used for duration formatting.
+	secondsPerMinute = 60
+	minutesPerHour   = 60
+
+	// Bit-rate thresholds for human-readable upload speed formatting.
+	bitsPerGbit = 1e9
+	bitsPerMbit = 1e6
+	bitsPerKbit = 1e3
+
+	// ellipsis prefixes truncated paths and suffixes shortened hashes.
+	ellipsis = "..."
+
+	// hashPrefixLen is how many hex characters of a blob hash to show in logs.
+	hashPrefixLen = 8
+)
+
 // ProgressStats holds atomic counters for progress tracking
 type ProgressStats struct {
 	FilesScanned     atomic.Int64 // Total files seen during scan (includes skipped)
@@ -64,7 +91,7 @@ type UploadInfo struct {
 // ProgressReporter handles periodic progress reporting
 type ProgressReporter struct {
 	stats         *ProgressStats
-	ctx           context.Context
+	ctx           context.Context //nolint:containedctx // bound at construction
 	cancel        context.CancelFunc
 	wg            sync.WaitGroup
 	detailTicker  *time.Ticker
@@ -127,6 +154,161 @@ func (pr *ProgressReporter) SetTotalSize(size int64) {
 	pr.stats.ProcessStartTime.Store(time.Now().UTC())
 }
 
+// Helper functions
+
+func formatDuration(d time.Duration) string {
+	if d < 0 {
+		return "unknown"
+	}
+
+	if d < time.Minute {
+		return fmt.Sprintf("%ds", int(d.Seconds()))
+	}
+
+	if d < time.Hour {
+		return fmt.Sprintf("%dm%ds", int(d.Minutes()), int(d.Seconds())%secondsPerMinute)
+	}
+
+	return fmt.Sprintf("%dh%dm", int(d.Hours()), int(d.Minutes())%minutesPerHour)
+}
+
+func formatPercent(numerator, denominator int64) string {
+	if denominator == 0 {
+		return "0.0%"
+	}
+
+	return fmt.Sprintf("%.1f%%", float64(numerator)/float64(denominator)*percentScale)
+}
+
+func formatRatio(compressed, uncompressed int64) string {
+	if uncompressed == 0 {
+		return "1.00"
+	}
+
+	ratio := float64(compressed) / float64(uncompressed)
+
+	return fmt.Sprintf("%.2f", ratio)
+}
+
+func truncatePath(path string, maxLen int) string {
+	if len(path) <= maxLen {
+		return path
+	}
+	// Keep the last maxLen-len(ellipsis) characters and prepend the ellipsis.
+	return ellipsis + path[len(path)-(maxLen-len(ellipsis)):]
+}
+
+// safeUint64 converts a non-negative int64 counter to uint64 for display,
+// clamping negative values to zero.
+func safeUint64(n int64) uint64 {
+	if n < 0 {
+		return 0
+	}
+
+	return uint64(n)
+}
+
+// ReportUploadStart marks the beginning of a blob upload
+func (pr *ProgressReporter) ReportUploadStart(blobHash string, size int64) {
+	info := &UploadInfo{
+		BlobHash:  blobHash,
+		Size:      size,
+		StartTime: time.Now().UTC(),
+	}
+	pr.stats.CurrentUpload.Store(info)
+
+	// Log the start of upload
+	log.Info("Starting blob upload",
+		"hash", blobHash[:hashPrefixLen]+ellipsis,
+		"size", humanize.Bytes(safeUint64(size)))
+}
+
+// ReportUploadComplete marks the completion of a blob upload
+func (pr *ProgressReporter) ReportUploadComplete(
+	blobHash string, size int64, duration time.Duration,
+) {
+	// Clear current upload
+	pr.stats.CurrentUpload.Store((*UploadInfo)(nil))
+
+	// Add to total upload duration
+	pr.stats.UploadDurationMs.Add(duration.Milliseconds())
+
+	// Calculate speed
+	if duration < time.Millisecond {
+		duration = time.Millisecond
+	}
+
+	bytesPerSec := float64(size) / duration.Seconds()
+	bitsPerSec := bytesPerSec * bitsPerByte
+
+	// Format speed
+	var speedStr string
+
+	switch {
+	case bitsPerSec >= bitsPerGbit:
+		speedStr = fmt.Sprintf("%.1fGbit/sec", bitsPerSec/bitsPerGbit)
+	case bitsPerSec >= bitsPerMbit:
+		speedStr = fmt.Sprintf("%.0fMbit/sec", bitsPerSec/bitsPerMbit)
+	case bitsPerSec >= bitsPerKbit:
+		speedStr = fmt.Sprintf("%.0fKbit/sec", bitsPerSec/bitsPerKbit)
+	default:
+		speedStr = fmt.Sprintf("%.0fbit/sec", bitsPerSec)
+	}
+
+	log.Info("Blob upload completed",
+		"hash", blobHash[:hashPrefixLen]+ellipsis,
+		"size", humanize.Bytes(safeUint64(size)),
+		"duration", formatDuration(duration),
+		"speed", speedStr)
+}
+
+// UpdateChunkingActivity updates the last chunking time
+func (pr *ProgressReporter) UpdateChunkingActivity() {
+	pr.stats.mu.Lock()
+	pr.stats.lastChunkingTime = time.Now().UTC()
+	pr.stats.mu.Unlock()
+}
+
+// ReportUploadProgress reports current upload progress with instantaneous speed
+func (pr *ProgressReporter) ReportUploadProgress(
+	blobHash string, bytesUploaded, totalSize int64, instantSpeed float64,
+) {
+	// Update the current upload info with progress
+	uploadInfo, ok := pr.stats.CurrentUpload.Load().(*UploadInfo)
+	if ok && uploadInfo != nil {
+		now := time.Now()
+
+		// Only log at the configured interval
+		if now.Sub(uploadInfo.LastLogTime) >= UploadProgressInterval {
+			// Format speed in bits/second using humanize
+			bitsPerSec := instantSpeed * bitsPerByte
+			speedStr := humanize.SI(bitsPerSec, "bit/sec")
+
+			percent := float64(bytesUploaded) / float64(totalSize) * percentScale
+
+			// Calculate ETA based on current speed
+			etaStr := "unknown"
+
+			if instantSpeed > 0 && bytesUploaded < totalSize {
+				remainingBytes := totalSize - bytesUploaded
+				remainingSeconds := float64(remainingBytes) / instantSpeed
+				eta := time.Duration(remainingSeconds * float64(time.Second))
+				etaStr = formatDuration(eta)
+			}
+
+			log.Info("Blob upload progress",
+				"hash", blobHash[:hashPrefixLen]+ellipsis,
+				"progress", fmt.Sprintf("%.1f%%", percent),
+				"uploaded", humanize.Bytes(safeUint64(bytesUploaded)),
+				"total", humanize.Bytes(safeUint64(totalSize)),
+				"speed", speedStr,
+				"eta", etaStr)
+
+			uploadInfo.LastLogTime = now
+		}
+	}
+}
+
 // run is the main progress reporting loop
 func (pr *ProgressReporter) run() {
 	defer pr.wg.Done()
@@ -150,9 +332,11 @@ func (pr *ProgressReporter) run() {
 // printSummaryStatus prints a one-line status update
 func (pr *ProgressReporter) printSummaryStatus() {
 	// Check if we're currently uploading
-	if uploadInfo, ok := pr.stats.CurrentUpload.Load().(*UploadInfo); ok && uploadInfo != nil {
+	uploadInfo, ok := pr.stats.CurrentUpload.Load().(*UploadInfo)
+	if ok && uploadInfo != nil {
 		// Show upload progress instead
 		pr.printUploadProgress(uploadInfo)
+
 		return
 	}
 
@@ -171,20 +355,22 @@ func (pr *ProgressReporter) printSummaryStatus() {
 	bytesSkipped := pr.stats.BytesSkipped.Load()
 	bytesProcessed := pr.stats.BytesProcessed.Load()
 	totalSize := pr.stats.TotalSize.Load()
-	currentFile := pr.stats.CurrentFile.Load().(string)
+	currentFile, _ := pr.stats.CurrentFile.Load().(string)
 
 	// Calculate ETA if we have total size and are processing
 	etaStr := ""
+
 	if totalSize > 0 && bytesProcessed > 0 {
 		processStart, ok := pr.stats.ProcessStartTime.Load().(time.Time)
 		if ok && !processStart.IsZero() {
 			processElapsed := time.Since(processStart)
+
 			rate := float64(bytesProcessed) / processElapsed.Seconds()
 			if rate > 0 {
 				remainingBytes := totalSize - bytesProcessed
 				remainingSeconds := float64(remainingBytes) / rate
 				eta := time.Duration(remainingSeconds * float64(time.Second))
-				etaStr = fmt.Sprintf(" | ETA: %s", formatDuration(eta))
+				etaStr = " | ETA: " + formatDuration(eta)
 			}
 		}
 	}
@@ -198,15 +384,15 @@ func (pr *ProgressReporter) printSummaryStatus() {
 	status := fmt.Sprintf("Snapshot progress: %d/%d files, %s/%s (%.1f%%), %s/s%s",
 		filesProcessed,
 		totalFiles,
-		humanize.Bytes(uint64(bytesProcessed)),
-		humanize.Bytes(uint64(totalSize)),
-		float64(bytesProcessed)/float64(totalSize)*100,
+		humanize.Bytes(safeUint64(bytesProcessed)),
+		humanize.Bytes(safeUint64(totalSize)),
+		float64(bytesProcessed)/float64(totalSize)*percentScale,
 		humanize.Bytes(uint64(rate)),
 		etaStr,
 	)
 
 	if currentFile != "" {
-		status += fmt.Sprintf(" | Current: %s", truncatePath(currentFile, 40))
+		status += " | Current: " + truncatePath(currentFile, currentFileMaxLen)
 	}
 
 	log.Info(status)
@@ -229,7 +415,7 @@ func (pr *ProgressReporter) printDetailedStatus() {
 	blobsCreated := pr.stats.BlobsCreated.Load()
 	blobsUploaded := pr.stats.BlobsUploaded.Load()
 	bytesUploaded := pr.stats.BytesUploaded.Load()
-	currentFile := pr.stats.CurrentFile.Load().(string)
+	currentFile, _ := pr.stats.CurrentFile.Load().(string)
 
 	totalBytes := bytesScanned + bytesSkipped
 	rate := float64(totalBytes) / elapsed.Seconds()
@@ -242,16 +428,17 @@ func (pr *ProgressReporter) printDetailedStatus() {
 		processStart, ok := pr.stats.ProcessStartTime.Load().(time.Time)
 		if ok && !processStart.IsZero() {
 			processElapsed := time.Since(processStart)
+
 			processRate := float64(bytesProcessed) / processElapsed.Seconds()
 			if processRate > 0 {
 				remainingBytes := totalSize - bytesProcessed
 				remainingSeconds := float64(remainingBytes) / processRate
 				eta := time.Duration(remainingSeconds * float64(time.Second))
-				percentComplete := float64(bytesProcessed) / float64(totalSize) * 100
+				percentComplete := float64(bytesProcessed) / float64(totalSize) * percentScale
 				log.Info("Overall progress",
 					"percent", fmt.Sprintf("%.1f%%", percentComplete),
-					"processed", humanize.Bytes(uint64(bytesProcessed)),
-					"total", humanize.Bytes(uint64(totalSize)),
+					"processed", humanize.Bytes(safeUint64(bytesProcessed)),
+					"total", humanize.Bytes(safeUint64(totalSize)),
 					"rate", humanize.Bytes(uint64(processRate))+"/s",
 					"eta", formatDuration(eta))
 			}
@@ -264,9 +451,9 @@ func (pr *ProgressReporter) printDetailedStatus() {
 		"total", filesScanned,
 		"skip_rate", formatPercent(filesSkipped, filesScanned))
 	log.Info("Data scanned",
-		"new", humanize.Bytes(uint64(bytesScanned)),
-		"skipped", humanize.Bytes(uint64(bytesSkipped)),
-		"total", humanize.Bytes(uint64(totalBytes)),
+		"new", humanize.Bytes(safeUint64(bytesScanned)),
+		"skipped", humanize.Bytes(safeUint64(bytesSkipped)),
+		"total", humanize.Bytes(safeUint64(totalBytes)),
 		"scan_rate", humanize.Bytes(uint64(rate))+"/s")
 	log.Info("Chunks created", "count", chunksCreated)
 	log.Info("Blobs status",
@@ -274,146 +461,18 @@ func (pr *ProgressReporter) printDetailedStatus() {
 		"uploaded", blobsUploaded,
 		"pending", blobsCreated-blobsUploaded)
 	log.Info("Total uploaded to remote",
-		"uploaded", humanize.Bytes(uint64(bytesUploaded)),
+		"uploaded", humanize.Bytes(safeUint64(bytesUploaded)),
 		"compression_ratio", formatRatio(bytesUploaded, bytesScanned))
+
 	if currentFile != "" {
 		log.Info("Current file", "path", currentFile)
 	}
+
 	log.Notice("=============================")
 }
 
-// Helper functions
-
-func formatDuration(d time.Duration) string {
-	if d < 0 {
-		return "unknown"
-	}
-	if d < time.Minute {
-		return fmt.Sprintf("%ds", int(d.Seconds()))
-	}
-	if d < time.Hour {
-		return fmt.Sprintf("%dm%ds", int(d.Minutes()), int(d.Seconds())%60)
-	}
-	return fmt.Sprintf("%dh%dm", int(d.Hours()), int(d.Minutes())%60)
-}
-
-func formatPercent(numerator, denominator int64) string {
-	if denominator == 0 {
-		return "0.0%"
-	}
-	return fmt.Sprintf("%.1f%%", float64(numerator)/float64(denominator)*100)
-}
-
-func formatRatio(compressed, uncompressed int64) string {
-	if uncompressed == 0 {
-		return "1.00"
-	}
-	ratio := float64(compressed) / float64(uncompressed)
-	return fmt.Sprintf("%.2f", ratio)
-}
-
-func truncatePath(path string, maxLen int) string {
-	if len(path) <= maxLen {
-		return path
-	}
-	// Keep the last maxLen-3 characters and prepend "..."
-	return "..." + path[len(path)-(maxLen-3):]
-}
-
 // printUploadProgress prints upload progress
-func (pr *ProgressReporter) printUploadProgress(info *UploadInfo) {
+func (pr *ProgressReporter) printUploadProgress(_ *UploadInfo) {
 	// This function is called repeatedly during upload, not just at start
 	// Don't print anything here - the actual progress is shown by ReportUploadProgress
 }
-
-// ReportUploadStart marks the beginning of a blob upload
-func (pr *ProgressReporter) ReportUploadStart(blobHash string, size int64) {
-	info := &UploadInfo{
-		BlobHash:  blobHash,
-		Size:      size,
-		StartTime: time.Now().UTC(),
-	}
-	pr.stats.CurrentUpload.Store(info)
-
-	// Log the start of upload
-	log.Info("Starting blob upload",
-		"hash", blobHash[:8]+"...",
-		"size", humanize.Bytes(uint64(size)))
-}
-
-// ReportUploadComplete marks the completion of a blob upload
-func (pr *ProgressReporter) ReportUploadComplete(blobHash string, size int64, duration time.Duration) {
-	// Clear current upload
-	pr.stats.CurrentUpload.Store((*UploadInfo)(nil))
-
-	// Add to total upload duration
-	pr.stats.UploadDurationMs.Add(duration.Milliseconds())
-
-	// Calculate speed
-	if duration < time.Millisecond {
-		duration = time.Millisecond
-	}
-	bytesPerSec := float64(size) / duration.Seconds()
-	bitsPerSec := bytesPerSec * 8
-
-	// Format speed
-	var speedStr string
-	if bitsPerSec >= 1e9 {
-		speedStr = fmt.Sprintf("%.1fGbit/sec", bitsPerSec/1e9)
-	} else if bitsPerSec >= 1e6 {
-		speedStr = fmt.Sprintf("%.0fMbit/sec", bitsPerSec/1e6)
-	} else if bitsPerSec >= 1e3 {
-		speedStr = fmt.Sprintf("%.0fKbit/sec", bitsPerSec/1e3)
-	} else {
-		speedStr = fmt.Sprintf("%.0fbit/sec", bitsPerSec)
-	}
-
-	log.Info("Blob upload completed",
-		"hash", blobHash[:8]+"...",
-		"size", humanize.Bytes(uint64(size)),
-		"duration", formatDuration(duration),
-		"speed", speedStr)
-}
-
-// UpdateChunkingActivity updates the last chunking time
-func (pr *ProgressReporter) UpdateChunkingActivity() {
-	pr.stats.mu.Lock()
-	pr.stats.lastChunkingTime = time.Now().UTC()
-	pr.stats.mu.Unlock()
-}
-
-// ReportUploadProgress reports current upload progress with instantaneous speed
-func (pr *ProgressReporter) ReportUploadProgress(blobHash string, bytesUploaded, totalSize int64, instantSpeed float64) {
-	// Update the current upload info with progress
-	if uploadInfo, ok := pr.stats.CurrentUpload.Load().(*UploadInfo); ok && uploadInfo != nil {
-		now := time.Now()
-
-		// Only log at the configured interval
-		if now.Sub(uploadInfo.LastLogTime) >= UploadProgressInterval {
-			// Format speed in bits/second using humanize
-			bitsPerSec := instantSpeed * 8
-			speedStr := humanize.SI(bitsPerSec, "bit/sec")
-
-			percent := float64(bytesUploaded) / float64(totalSize) * 100
-
-			// Calculate ETA based on current speed
-			etaStr := "unknown"
-			if instantSpeed > 0 && bytesUploaded < totalSize {
-				remainingBytes := totalSize - bytesUploaded
-				remainingSeconds := float64(remainingBytes) / instantSpeed
-				eta := time.Duration(remainingSeconds * float64(time.Second))
-				etaStr = formatDuration(eta)
-			}
-
-			log.Info("Blob upload progress",
-				"hash", blobHash[:8]+"...",
-				"progress", fmt.Sprintf("%.1f%%", percent),
-				"uploaded", humanize.Bytes(uint64(bytesUploaded)),
-				"total", humanize.Bytes(uint64(totalSize)),
-				"speed", speedStr,
-				"eta", etaStr)
-
-			uploadInfo.LastLogTime = now
-		}
-	}
-}

internal/snapshot/remotekey.go

@@ -36,5 +36,6 @@ const remoteKeyPrefix = "vaultik|"
 func RemoteSnapshotKey(snapshotID string) string {
 	first := sha256.Sum256([]byte(remoteKeyPrefix + snapshotID))
 	second := sha256.Sum256(first[:])
+
 	return hex.EncodeToString(second[:])
 }

internal/snapshot/scanner_test.go

@@ -3,6 +3,7 @@ package snapshot_test
 import (
 	"context"
 	"database/sql"
+	"os"
 	"path/filepath"
 	"testing"
 	"time"
@@ -14,70 +15,37 @@ import (
 	"sneak.berlin/go/vaultik/internal/types"
 )
 
-func TestScannerSimpleDirectory(t *testing.T) {
-	// Initialize logger for tests
+// Shared test fixture values for the snapshot_test package.
+const (
+	// testHost is the hostname recorded on test snapshot rows.
+	testHost = "test-host"
+
+	// testVersion is the vaultik version recorded on test snapshot rows.
+	testVersion = "test"
+
+	// testAgePublicKey is the fixed age public key used for test encryption.
+	testAgePublicKey = "age1ezrjmfpwsc95svdg0y54mums3zevgzu0x0ecq2f7tp8a05gl0sjq9q9wjg"
+)
+
+// TestMain initializes the shared logger once, before any tests run, so
+// parallel tests never race on the logger's global state.
+func TestMain(m *testing.M) {
 	log.Initialize(log.Config{})
+	os.Exit(m.Run())
+}
 
-	// Create in-memory filesystem
-	fs := afero.NewMemMapFs()
+// createTestSnapshotRecord inserts an empty snapshot row used as the
+// association target for scan tests.
+func createTestSnapshotRecord(
+	ctx context.Context, t *testing.T, repos *database.Repositories, snapshotID string,
+) {
+	t.Helper()
 
-	// Create test directory structure
-	testFiles := map[string]string{
-		"/source/file1.txt":         "Hello, world!",                // 13 bytes
-		"/source/file2.txt":         "This is another file",         // 20 bytes
-		"/source/subdir/file3.txt":  "File in subdirectory",         // 20 bytes
-		"/source/subdir/file4.txt":  "Another file in subdirectory", // 28 bytes
-		"/source/empty.txt":         "",                             // 0 bytes
-		"/source/subdir2/file5.txt": "Yet another file",             // 16 bytes
-	}
-
-	// Create files with specific times
-	testTime := time.Date(2024, 1, 1, 12, 0, 0, 0, time.UTC)
-	for path, content := range testFiles {
-		dir := filepath.Dir(path)
-		if err := fs.MkdirAll(dir, 0755); err != nil {
-			t.Fatalf("failed to create directory %s: %v", dir, err)
-		}
-		if err := afero.WriteFile(fs, path, []byte(content), 0644); err != nil {
-			t.Fatalf("failed to write file %s: %v", path, err)
-		}
-		// Set times
-		if err := fs.Chtimes(path, testTime, testTime); err != nil {
-			t.Fatalf("failed to set times for %s: %v", path, err)
-		}
-	}
-
-	// Create test database
-	db, err := database.NewTestDB()
-	if err != nil {
-		t.Fatalf("failed to create test database: %v", err)
-	}
-	defer func() {
-		if err := db.Close(); err != nil {
-			t.Errorf("failed to close database: %v", err)
-		}
-	}()
-
-	repos := database.NewRepositories(db)
-
-	// Create scanner
-	scanner := snapshot.NewScanner(snapshot.ScannerConfig{
-		FS:               fs,
-		ChunkSize:        int64(1024 * 16), // 16KB chunks for testing
-		Repositories:     repos,
-		MaxBlobSize:      int64(1024 * 1024), // 1MB blobs
-		CompressionLevel: 3,
-		AgeRecipients:    []string{"age1ezrjmfpwsc95svdg0y54mums3zevgzu0x0ecq2f7tp8a05gl0sjq9q9wjg"}, // Test public key
-	})
-
-	// Create a snapshot record for testing
-	ctx := context.Background()
-	snapshotID := "test-snapshot-001"
-	err = repos.WithTx(ctx, func(ctx context.Context, tx *sql.Tx) error {
+	err := repos.WithTx(ctx, func(ctx context.Context, tx *sql.Tx) error {
 		snapshot := &database.Snapshot{
 			ID:               types.SnapshotID(snapshotID),
-			Hostname:         "test-host",
-			VaultikVersion:   "test",
+			Hostname:         testHost,
+			VaultikVersion:   testVersion,
 			StartedAt:        time.Now(),
 			CompletedAt:      nil,
 			FileCount:        0,
@@ -87,28 +55,20 @@ func TestScannerSimpleDirectory(t *testing.T) {
 			BlobSize:         0,
 			CompressionRatio: 1.0,
 		}
+
 		return repos.Snapshots.Create(ctx, tx, snapshot)
 	})
 	if err != nil {
 		t.Fatalf("failed to create snapshot: %v", err)
 	}
+}
 
-	// Scan the directory
-	var result *snapshot.ScanResult
-	result, err = scanner.Scan(ctx, "/source", snapshotID)
-	if err != nil {
-		t.Fatalf("scan failed: %v", err)
-	}
-
-	// Verify results - we only scan regular files, not directories
-	if result.FilesScanned != 6 {
-		t.Errorf("expected 6 files scanned, got %d", result.FilesScanned)
-	}
-
-	// Total bytes should be the sum of all file contents
-	if result.BytesScanned < 97 { // At minimum we have 97 bytes of file content
-		t.Errorf("expected at least 97 bytes scanned, got %d", result.BytesScanned)
-	}
+// verifySimpleScanDatabase checks the database contents produced by
+// TestScannerSimpleDirectory's scan.
+func verifySimpleScanDatabase(
+	ctx context.Context, t *testing.T, repos *database.Repositories,
+) {
+	t.Helper()
 
 	// Verify files in database - includes regular files and directories
 	files, err := repos.Files.ListByPrefix(ctx, "/source")
@@ -159,9 +119,99 @@ func TestScannerSimpleDirectory(t *testing.T) {
 	}
 }
 
+func TestScannerSimpleDirectory(t *testing.T) {
+	// Initialize logger for tests
+	log.Initialize(log.Config{})
+	t.Parallel()
+
+	// Create in-memory filesystem
+	fs := afero.NewMemMapFs()
+
+	// Create test directory structure
+	testFiles := map[string]string{
+		"/source/file1.txt":         "Hello, world!",                // 13 bytes
+		"/source/file2.txt":         "This is another file",         // 20 bytes
+		"/source/subdir/file3.txt":  "File in subdirectory",         // 20 bytes
+		"/source/subdir/file4.txt":  "Another file in subdirectory", // 28 bytes
+		"/source/empty.txt":         "",                             // 0 bytes
+		"/source/subdir2/file5.txt": "Yet another file",             // 16 bytes
+	}
+
+	// Create files with specific times
+	testTime := time.Date(2024, 1, 1, 12, 0, 0, 0, time.UTC)
+
+	for path, content := range testFiles {
+		dir := filepath.Dir(path)
+
+		err := fs.MkdirAll(dir, 0755)
+		if err != nil {
+			t.Fatalf("failed to create directory %s: %v", dir, err)
+		}
+
+		err = afero.WriteFile(fs, path, []byte(content), 0644)
+		if err != nil {
+			t.Fatalf("failed to write file %s: %v", path, err)
+		}
+		// Set times
+		err = fs.Chtimes(path, testTime, testTime)
+		if err != nil {
+			t.Fatalf("failed to set times for %s: %v", path, err)
+		}
+	}
+
+	// Create test database
+	db, err := database.NewTestDB()
+	if err != nil {
+		t.Fatalf("failed to create test database: %v", err)
+	}
+	defer func() {
+		err := db.Close()
+		if err != nil {
+			t.Errorf("failed to close database: %v", err)
+		}
+	}()
+
+	repos := database.NewRepositories(db)
+
+	// Create scanner
+	scanner := snapshot.NewScanner(snapshot.ScannerConfig{
+		FS:               fs,
+		ChunkSize:        int64(1024 * 16), // 16KB chunks for testing
+		Repositories:     repos,
+		MaxBlobSize:      int64(1024 * 1024), // 1MB blobs
+		CompressionLevel: 3,
+		AgeRecipients:    []string{testAgePublicKey},
+	})
+
+	// Create a snapshot record for testing
+	ctx := context.Background()
+	snapshotID := "test-snapshot-001"
+
+	createTestSnapshotRecord(ctx, t, repos, snapshotID)
+
+	// Scan the directory
+	result, err := scanner.Scan(ctx, "/source", snapshotID)
+	if err != nil {
+		t.Fatalf("scan failed: %v", err)
+	}
+
+	// Verify results - we only scan regular files, not directories
+	if result.FilesScanned != 6 {
+		t.Errorf("expected 6 files scanned, got %d", result.FilesScanned)
+	}
+
+	// Total bytes should be the sum of all file contents
+	if result.BytesScanned < 97 { // At minimum we have 97 bytes of file content
+		t.Errorf("expected at least 97 bytes scanned, got %d", result.BytesScanned)
+	}
+
+	verifySimpleScanDatabase(ctx, t, repos)
+}
+
 func TestScannerLargeFile(t *testing.T) {
 	// Initialize logger for tests
 	log.Initialize(log.Config{})
+	t.Parallel()
 
 	// Create in-memory filesystem
 	fs := afero.NewMemMapFs()
@@ -170,15 +220,19 @@ func TestScannerLargeFile(t *testing.T) {
 	// Use random content to ensure good chunk boundaries
 	largeContent := make([]byte, 1024*1024) // 1MB
 	// Fill with pseudo-random data to ensure chunk boundaries
-	for i := 0; i < len(largeContent); i++ {
+	for i := range largeContent {
 		// Simple pseudo-random generator for deterministic tests
+		//nolint:gosec // G115: intentional byte truncation of test data
 		largeContent[i] = byte((i * 7919) ^ (i >> 3))
 	}
 
-	if err := fs.MkdirAll("/source", 0755); err != nil {
+	err := fs.MkdirAll("/source", 0755)
+	if err != nil {
 		t.Fatal(err)
 	}
-	if err := afero.WriteFile(fs, "/source/large.bin", largeContent, 0644); err != nil {
+
+	err = afero.WriteFile(fs, "/source/large.bin", largeContent, 0644)
+	if err != nil {
 		t.Fatal(err)
 	}
 
@@ -188,7 +242,8 @@ func TestScannerLargeFile(t *testing.T) {
 		t.Fatalf("failed to create test database: %v", err)
 	}
 	defer func() {
-		if err := db.Close(); err != nil {
+		err := db.Close()
+		if err != nil {
 			t.Errorf("failed to close database: %v", err)
 		}
 	}()
@@ -202,35 +257,17 @@ func TestScannerLargeFile(t *testing.T) {
 		Repositories:     repos,
 		MaxBlobSize:      int64(1024 * 1024),
 		CompressionLevel: 3,
-		AgeRecipients:    []string{"age1ezrjmfpwsc95svdg0y54mums3zevgzu0x0ecq2f7tp8a05gl0sjq9q9wjg"}, // Test public key
+		AgeRecipients:    []string{testAgePublicKey},
 	})
 
 	// Create a snapshot record for testing
 	ctx := context.Background()
 	snapshotID := "test-snapshot-001"
-	err = repos.WithTx(ctx, func(ctx context.Context, tx *sql.Tx) error {
-		snapshot := &database.Snapshot{
-			ID:               types.SnapshotID(snapshotID),
-			Hostname:         "test-host",
-			VaultikVersion:   "test",
-			StartedAt:        time.Now(),
-			CompletedAt:      nil,
-			FileCount:        0,
-			ChunkCount:       0,
-			BlobCount:        0,
-			TotalSize:        0,
-			BlobSize:         0,
-			CompressionRatio: 1.0,
-		}
-		return repos.Snapshots.Create(ctx, tx, snapshot)
-	})
-	if err != nil {
-		t.Fatalf("failed to create snapshot: %v", err)
-	}
+
+	createTestSnapshotRecord(ctx, t, repos, snapshotID)
 
 	// Scan the directory
-	var result *snapshot.ScanResult
-	result, err = scanner.Scan(ctx, "/source", snapshotID)
+	result, err := scanner.Scan(ctx, "/source", snapshotID)
 	if err != nil {
 		t.Fatalf("scan failed: %v", err)
 	}
@@ -242,7 +279,8 @@ func TestScannerLargeFile(t *testing.T) {
 
 	// The file size should be at least 1MB
 	if result.BytesScanned < 1024*1024 {
-		t.Errorf("expected at least %d bytes scanned, got %d", 1024*1024, result.BytesScanned)
+		t.Errorf("expected at least %d bytes scanned, got %d",
+			1024*1024, result.BytesScanned)
 	}
 
 	// Verify chunks

internal/snapshot/snapshot_test.go

@@ -1,3 +1,4 @@
+//nolint:testpackage // exercises unexported SnapshotManager internals
 package snapshot
 
 import (
@@ -33,12 +34,69 @@ func copyFile(fs afero.Fs, src, dst string) error {
 	defer func() { _ = destFile.Close() }()
 
 	_, err = io.Copy(destFile, sourceFile)
+
 	return err
 }
 
+// verifyCleanedDB opens the cleaned database and checks that the kept
+// snapshot survived while the orphan file and chunk were removed.
+func verifyCleanedDB(
+	ctx context.Context,
+	t *testing.T,
+	tempDBPath, snapshotID string,
+	file *database.File,
+	chunk *database.Chunk,
+) {
+	t.Helper()
+
+	cleanedDB, err := database.New(ctx, tempDBPath)
+	if err != nil {
+		t.Fatalf("failed to open cleaned database: %v", err)
+	}
+	defer func() {
+		err := cleanedDB.Close()
+		if err != nil {
+			t.Errorf("failed to close database: %v", err)
+		}
+	}()
+
+	cleanedRepos := database.NewRepositories(cleanedDB)
+
+	// Verify snapshot exists
+	verifySnapshot, err := cleanedRepos.Snapshots.GetByID(ctx, snapshotID)
+	if err != nil {
+		t.Fatalf("failed to get snapshot: %v", err)
+	}
+
+	if verifySnapshot == nil {
+		t.Error("snapshot should exist")
+	}
+
+	// Verify orphan file is gone
+	f, err := cleanedRepos.Files.GetByPath(ctx, file.Path.String())
+	if err != nil {
+		t.Fatalf("failed to check file: %v", err)
+	}
+
+	if f != nil {
+		t.Error("orphan file should not exist")
+	}
+
+	// Verify orphan chunk is gone
+	c, err := cleanedRepos.Chunks.GetByHash(ctx, chunk.ChunkHash.String())
+	if err != nil {
+		t.Fatalf("failed to check chunk: %v", err)
+	}
+
+	if c != nil {
+		t.Error("orphan chunk should not exist")
+	}
+}
+
 func TestCleanSnapshotDBEmptySnapshot(t *testing.T) {
 	// Initialize logger
 	log.Initialize(log.Config{})
+	t.Parallel()
 
 	ctx := context.Background()
 	fs := afero.NewOsFs()
@@ -46,6 +104,7 @@ func TestCleanSnapshotDBEmptySnapshot(t *testing.T) {
 	// Create a test database
 	tempDir := t.TempDir()
 	dbPath := filepath.Join(tempDir, "test.db")
+
 	db, err := database.New(ctx, dbPath)
 	if err != nil {
 		t.Fatalf("failed to create database: %v", err)
@@ -71,9 +130,11 @@ func TestCleanSnapshotDBEmptySnapshot(t *testing.T) {
 	chunk := &database.Chunk{ChunkHash: "orphan-chunk", Size: 500}
 
 	err = repos.WithTx(ctx, func(ctx context.Context, tx *sql.Tx) error {
-		if err := repos.Files.Create(ctx, tx, file); err != nil {
+		err := repos.Files.Create(ctx, tx, file)
+		if err != nil {
 			return err
 		}
+
 		return repos.Chunks.Create(ctx, tx, chunk)
 	})
 	if err != nil {
@@ -81,13 +142,16 @@ func TestCleanSnapshotDBEmptySnapshot(t *testing.T) {
 	}
 
 	// Close the database
-	if err := db.Close(); err != nil {
+	err = db.Close()
+	if err != nil {
 		t.Fatalf("failed to close database: %v", err)
 	}
 
 	// Copy database
 	tempDBPath := filepath.Join(tempDir, "temp.db")
-	if err := copyFile(fs, dbPath, tempDBPath); err != nil {
+
+	err = copyFile(fs, dbPath, tempDBPath)
+	if err != nil {
 		t.Fatalf("failed to copy database: %v", err)
 	}
 
@@ -101,54 +165,20 @@ func TestCleanSnapshotDBEmptySnapshot(t *testing.T) {
 		config: cfg,
 		fs:     fs,
 	}
-	if _, err := sm.cleanSnapshotDB(ctx, tempDBPath, snapshot.ID.String()); err != nil {
+
+	_, err = sm.cleanSnapshotDB(ctx, tempDBPath, snapshot.ID.String())
+	if err != nil {
 		t.Fatalf("failed to clean snapshot database: %v", err)
 	}
 
 	// Verify the cleaned database
-	cleanedDB, err := database.New(ctx, tempDBPath)
-	if err != nil {
-		t.Fatalf("failed to open cleaned database: %v", err)
-	}
-	defer func() {
-		if err := cleanedDB.Close(); err != nil {
-			t.Errorf("failed to close database: %v", err)
-		}
-	}()
-
-	cleanedRepos := database.NewRepositories(cleanedDB)
-
-	// Verify snapshot exists
-	verifySnapshot, err := cleanedRepos.Snapshots.GetByID(ctx, snapshot.ID.String())
-	if err != nil {
-		t.Fatalf("failed to get snapshot: %v", err)
-	}
-	if verifySnapshot == nil {
-		t.Error("snapshot should exist")
-	}
-
-	// Verify orphan file is gone
-	f, err := cleanedRepos.Files.GetByPath(ctx, file.Path.String())
-	if err != nil {
-		t.Fatalf("failed to check file: %v", err)
-	}
-	if f != nil {
-		t.Error("orphan file should not exist")
-	}
-
-	// Verify orphan chunk is gone
-	c, err := cleanedRepos.Chunks.GetByHash(ctx, chunk.ChunkHash.String())
-	if err != nil {
-		t.Fatalf("failed to check chunk: %v", err)
-	}
-	if c != nil {
-		t.Error("orphan chunk should not exist")
-	}
+	verifyCleanedDB(ctx, t, tempDBPath, snapshot.ID.String(), file, chunk)
 }
 
 func TestCleanSnapshotDBNonExistentSnapshot(t *testing.T) {
 	// Initialize logger
 	log.Initialize(log.Config{})
+	t.Parallel()
 
 	ctx := context.Background()
 	fs := afero.NewOsFs()
@@ -156,19 +186,23 @@ func TestCleanSnapshotDBNonExistentSnapshot(t *testing.T) {
 	// Create a test database
 	tempDir := t.TempDir()
 	dbPath := filepath.Join(tempDir, "test.db")
+
 	db, err := database.New(ctx, dbPath)
 	if err != nil {
 		t.Fatalf("failed to create database: %v", err)
 	}
 
 	// Close immediately
-	if err := db.Close(); err != nil {
+	err = db.Close()
+	if err != nil {
 		t.Fatalf("failed to close database: %v", err)
 	}
 
 	// Copy database
 	tempDBPath := filepath.Join(tempDir, "temp.db")
-	if err := copyFile(fs, dbPath, tempDBPath); err != nil {
+
+	err = copyFile(fs, dbPath, tempDBPath)
+	if err != nil {
 		t.Fatalf("failed to copy database: %v", err)
 	}
 

internal/storage/file.go

@@ -42,18 +42,19 @@ func (f *FileStorer) SetFilesystem(fs afero.Fs) {
 	f.fs = fs
 }
 
-// fullPath returns the full filesystem path for a key.
-func (f *FileStorer) fullPath(key string) string {
-	return filepath.Join(f.basePath, key)
-}
+// storageDirPerm is the mode used for directories created under the
+// storage base path.
+const storageDirPerm = 0o755
 
 // Put stores data at the specified key.
-func (f *FileStorer) Put(ctx context.Context, key string, data io.Reader) error {
+func (f *FileStorer) Put(_ context.Context, key string, data io.Reader) error {
 	path := f.fullPath(key)
 
 	// Create parent directories
 	dir := filepath.Dir(path)
-	if err := f.fs.MkdirAll(dir, 0755); err != nil {
+
+	err := f.fs.MkdirAll(dir, storageDirPerm)
+	if err != nil {
 		return fmt.Errorf("creating directories: %w", err)
 	}
 
@@ -63,7 +64,8 @@ func (f *FileStorer) Put(ctx context.Context, key string, data io.Reader) error
 	}
 	defer func() { _ = file.Close() }()
 
-	if _, err := io.Copy(file, data); err != nil {
+	_, err = io.Copy(file, data)
+	if err != nil {
 		return fmt.Errorf("writing file: %w", err)
 	}
 
@@ -71,12 +73,17 @@ func (f *FileStorer) Put(ctx context.Context, key string, data io.Reader) error
 }
 
 // PutWithProgress stores data with progress reporting.
-func (f *FileStorer) PutWithProgress(ctx context.Context, key string, data io.Reader, size int64, progress ProgressCallback) error {
+func (f *FileStorer) PutWithProgress(
+	_ context.Context, key string, data io.Reader,
+	_ int64, progress ProgressCallback,
+) error {
 	path := f.fullPath(key)
 
 	// Create parent directories
 	dir := filepath.Dir(path)
-	if err := f.fs.MkdirAll(dir, 0755); err != nil {
+
+	err := f.fs.MkdirAll(dir, storageDirPerm)
+	if err != nil {
 		return fmt.Errorf("creating directories: %w", err)
 	}
 
@@ -92,7 +99,8 @@ func (f *FileStorer) PutWithProgress(ctx context.Context, key string, data io.Re
 		callback: progress,
 	}
 
-	if _, err := io.Copy(pw, data); err != nil {
+	_, err = io.Copy(pw, data)
+	if err != nil {
 		return fmt.Errorf("writing file: %w", err)
 	}
 
@@ -100,28 +108,34 @@ func (f *FileStorer) PutWithProgress(ctx context.Context, key string, data io.Re
 }
 
 // Get retrieves data from the specified key.
-func (f *FileStorer) Get(ctx context.Context, key string) (io.ReadCloser, error) {
+func (f *FileStorer) Get(_ context.Context, key string) (io.ReadCloser, error) {
 	path := f.fullPath(key)
+
 	file, err := f.fs.Open(path)
 	if err != nil {
 		if os.IsNotExist(err) {
 			return nil, ErrNotFound
 		}
+
 		return nil, fmt.Errorf("opening file: %w", err)
 	}
+
 	return file, nil
 }
 
 // Stat returns metadata about an object without retrieving its contents.
-func (f *FileStorer) Stat(ctx context.Context, key string) (*ObjectInfo, error) {
+func (f *FileStorer) Stat(_ context.Context, key string) (*ObjectInfo, error) {
 	path := f.fullPath(key)
+
 	info, err := f.fs.Stat(path)
 	if err != nil {
 		if os.IsNotExist(err) {
 			return nil, ErrNotFound
 		}
+
 		return nil, fmt.Errorf("stat file: %w", err)
 	}
+
 	return &ObjectInfo{
 		Key:  key,
 		Size: info.Size(),
@@ -129,21 +143,25 @@ func (f *FileStorer) Stat(ctx context.Context, key string) (*ObjectInfo, error)
 }
 
 // Delete removes an object.
-func (f *FileStorer) Delete(ctx context.Context, key string) error {
+func (f *FileStorer) Delete(_ context.Context, key string) error {
 	path := f.fullPath(key)
+
 	err := f.fs.Remove(path)
 	if os.IsNotExist(err) {
 		return nil // Match S3 behavior: no error if doesn't exist
 	}
+
 	if err != nil {
 		return fmt.Errorf("removing file: %w", err)
 	}
+
 	return nil
 }
 
 // List returns all keys with the given prefix.
 func (f *FileStorer) List(ctx context.Context, prefix string) ([]string, error) {
 	var keys []string
+
 	basePath := f.fullPath(prefix)
 
 	// Check if base path exists
@@ -151,6 +169,7 @@ func (f *FileStorer) List(ctx context.Context, prefix string) ([]string, error)
 	if err != nil {
 		return nil, fmt.Errorf("checking path: %w", err)
 	}
+
 	if !exists {
 		return keys, nil // Empty list for non-existent prefix
 	}
@@ -177,9 +196,9 @@ func (f *FileStorer) List(ctx context.Context, prefix string) ([]string, error)
 			relPath = strings.ReplaceAll(relPath, string(filepath.Separator), "/")
 			keys = append(keys, relPath)
 		}
+
 		return nil
 	})
-
 	if err != nil {
 		return nil, fmt.Errorf("walking directory: %w", err)
 	}
@@ -192,14 +211,17 @@ func (f *FileStorer) ListStream(ctx context.Context, prefix string) <-chan Objec
 	ch := make(chan ObjectInfo)
 	go func() {
 		defer close(ch)
+
 		basePath := f.fullPath(prefix)
 
 		// Check if base path exists
 		exists, err := afero.Exists(f.fs, basePath)
 		if err != nil {
 			ch <- ObjectInfo{Err: fmt.Errorf("checking path: %w", err)}
+
 			return
 		}
+
 		if !exists {
 			return // Empty channel for non-existent prefix
 		}
@@ -209,19 +231,22 @@ func (f *FileStorer) ListStream(ctx context.Context, prefix string) <-chan Objec
 			select {
 			case <-ctx.Done():
 				ch <- ObjectInfo{Err: ctx.Err()}
+
 				return ctx.Err()
 			default:
 			}
 
 			if err != nil {
 				ch <- ObjectInfo{Err: err}
-				return nil // Continue walking despite errors
+
+				return nil //nolint:nilerr // continue walking despite errors
 			}
 
 			if !info.IsDir() {
 				relPath, err := filepath.Rel(f.basePath, path)
 				if err != nil {
 					ch <- ObjectInfo{Err: fmt.Errorf("computing relative path: %w", err)}
+
 					return nil
 				}
 				// Normalize path separators
@@ -231,20 +256,27 @@ func (f *FileStorer) ListStream(ctx context.Context, prefix string) <-chan Objec
 					Size: info.Size(),
 				}
 			}
+
 			return nil
 		})
 	}()
+
 	return ch
 }
 
 // Info returns human-readable storage location information.
-func (f *FileStorer) Info() StorageInfo {
-	return StorageInfo{
-		Type:     "file",
+func (f *FileStorer) Info() Info {
+	return Info{
+		Type:     schemeFile,
 		Location: f.basePath,
 	}
 }
 
+// fullPath returns the full filesystem path for a key.
+func (f *FileStorer) fullPath(key string) string {
+	return filepath.Join(f.basePath, key)
+}
+
 // progressWriter wraps an io.Writer to track write progress.
 type progressWriter struct {
 	writer   io.Writer
@@ -257,10 +289,12 @@ func (pw *progressWriter) Write(p []byte) (int, error) {
 	if n > 0 {
 		pw.written += int64(n)
 		if pw.callback != nil {
-			if callbackErr := pw.callback(pw.written); callbackErr != nil {
+			callbackErr := pw.callback(pw.written)
+			if callbackErr != nil {
 				return n, callbackErr
 			}
 		}
 	}
+
 	return n, err
 }

internal/storage/module.go

@@ -10,9 +10,17 @@ import (
 	"sneak.berlin/go/vaultik/internal/s3"
 )
 
+// defaultS3Region is used when neither the URL nor the config specify one.
+const defaultS3Region = "us-east-1"
+
+// defaultS3Endpoint is the AWS endpoint used when none is configured.
+const defaultS3Endpoint = "s3.amazonaws.com"
+
 // Module exports storage functionality as an fx module.
 // It provides a Storer implementation based on the configured storage URL
 // or falls back to legacy S3 configuration.
+//
+//nolint:gochecknoglobals // fx module definitions are package globals
 var Module = fx.Module("storage",
 	fx.Provide(NewStorer),
 )
@@ -20,13 +28,17 @@ var Module = fx.Module("storage",
 // NewStorer creates a Storer based on configuration.
 // If StorageURL is set, it uses URL-based configuration.
 // Otherwise, it falls back to legacy S3 configuration.
+//
+//nolint:ireturn // fx provider intentionally returns the Storer interface
 func NewStorer(cfg *config.Config) (Storer, error) {
 	if cfg.StorageURL != "" {
 		return storerFromURL(cfg.StorageURL, cfg)
 	}
+
 	return storerFromLegacyS3Config(cfg)
 }
 
+//nolint:ireturn // factory intentionally returns the Storer interface
 func storerFromURL(rawURL string, cfg *config.Config) (Storer, error) {
 	parsed, err := ParseStorageURL(rawURL)
 	if err != nil {
@@ -34,28 +46,48 @@ func storerFromURL(rawURL string, cfg *config.Config) (Storer, error) {
 	}
 
 	switch parsed.Scheme {
-	case "file":
+	case schemeFile:
 		return NewFileStorer(parsed.Prefix)
 
-	case "s3":
+	case schemeS3:
+		return storerFromParsedS3URL(parsed, cfg)
+
+	case schemeRclone:
+		return NewRcloneStorer(
+			context.Background(), parsed.RcloneRemote, parsed.Prefix)
+
+	default:
+		return nil, fmt.Errorf("%w: %s", ErrUnsupportedStorage, parsed.Scheme)
+	}
+}
+
+// storerFromParsedS3URL builds an S3 storer from a parsed s3:// URL,
+// filling endpoint protocol and region defaults from the config.
+//
+//nolint:ireturn // factory intentionally returns the Storer interface
+func storerFromParsedS3URL(parsed *URL, cfg *config.Config) (Storer, error) {
 	// Build endpoint URL
 	endpoint := parsed.Endpoint
 	if endpoint == "" {
-			endpoint = "s3.amazonaws.com"
+		endpoint = defaultS3Endpoint
 	}
 
 	// Add protocol if not present
-		if parsed.UseSSL && !strings.HasPrefix(endpoint, "https://") && !strings.HasPrefix(endpoint, "http://") {
+	hasProtocol := strings.HasPrefix(endpoint, "https://") ||
+		strings.HasPrefix(endpoint, "http://")
+	if !hasProtocol {
+		if parsed.UseSSL {
 			endpoint = "https://" + endpoint
-		} else if !parsed.UseSSL && !strings.HasPrefix(endpoint, "http://") && !strings.HasPrefix(endpoint, "https://") {
+		} else {
 			endpoint = "http://" + endpoint
 		}
+	}
 
 	region := parsed.Region
 	if region == "" {
 		region = cfg.S3.Region
 		if region == "" {
-				region = "us-east-1"
+			region = defaultS3Region
 		}
 	}
 
@@ -71,21 +103,17 @@ func storerFromURL(rawURL string, cfg *config.Config) (Storer, error) {
 	if err != nil {
 		return nil, fmt.Errorf("creating S3 client: %w", err)
 	}
+
 	return NewS3Storer(client), nil
-
-	case "rclone":
-		return NewRcloneStorer(context.Background(), parsed.RcloneRemote, parsed.Prefix)
-
-	default:
-		return nil, fmt.Errorf("unsupported storage scheme: %s", parsed.Scheme)
-	}
 }
 
+//nolint:ireturn // factory intentionally returns the Storer interface
 func storerFromLegacyS3Config(cfg *config.Config) (Storer, error) {
 	endpoint := cfg.S3.Endpoint
 
 	// Ensure protocol is present
-	if !strings.HasPrefix(endpoint, "http://") && !strings.HasPrefix(endpoint, "https://") {
+	if !strings.HasPrefix(endpoint, "http://") &&
+		!strings.HasPrefix(endpoint, "https://") {
 		if cfg.S3.UseSSL {
 			endpoint = "https://" + endpoint
 		} else {
@@ -95,7 +123,7 @@ func storerFromLegacyS3Config(cfg *config.Config) (Storer, error) {
 
 	region := cfg.S3.Region
 	if region == "" {
-		region = "us-east-1"
+		region = defaultS3Region
 	}
 
 	client, err := s3.NewClient(context.Background(), s3.Config{
@@ -109,5 +137,6 @@ func storerFromLegacyS3Config(cfg *config.Config) (Storer, error) {
 	if err != nil {
 		return nil, fmt.Errorf("creating S3 client: %w", err)
 	}
+
 	return NewS3Storer(client), nil
 }

internal/storage/rclone.go

@@ -49,6 +49,7 @@ func NewRcloneStorer(ctx context.Context, remote, path string) (*RcloneStorer, e
 			strings.Contains(err.Error(), "failed to find remote") {
 			return nil, fmt.Errorf("%w: %s", ErrRemoteNotFound, remote)
 		}
+
 		return nil, fmt.Errorf("creating rclone filesystem: %w", err)
 	}
 
@@ -68,7 +69,8 @@ func (r *RcloneStorer) Put(ctx context.Context, key string, data io.Reader) erro
 	}
 
 	// Upload the object
-	_, err = operations.Rcat(ctx, r.fsys, key, io.NopCloser(bytes.NewReader(buf)), time.Now(), nil)
+	_, err = operations.Rcat(ctx, r.fsys, key,
+		io.NopCloser(bytes.NewReader(buf)), time.Now(), nil)
 	if err != nil {
 		return fmt.Errorf("uploading object: %w", err)
 	}
@@ -77,7 +79,10 @@ func (r *RcloneStorer) Put(ctx context.Context, key string, data io.Reader) erro
 }
 
 // PutWithProgress stores data with progress reporting.
-func (r *RcloneStorer) PutWithProgress(ctx context.Context, key string, data io.Reader, size int64, progress ProgressCallback) error {
+func (r *RcloneStorer) PutWithProgress(
+	ctx context.Context, key string, data io.Reader,
+	_ int64, progress ProgressCallback,
+) error {
 	// Wrap reader with progress tracking
 	pr := &progressReader{
 		reader:   data,
@@ -101,9 +106,11 @@ func (r *RcloneStorer) Get(ctx context.Context, key string) (io.ReadCloser, erro
 		if errors.Is(err, fs.ErrorObjectNotFound) {
 			return nil, ErrNotFound
 		}
+
 		if errors.Is(err, fs.ErrorDirNotFound) {
 			return nil, ErrNotFound
 		}
+
 		return nil, fmt.Errorf("getting object: %w", err)
 	}
 
@@ -123,9 +130,11 @@ func (r *RcloneStorer) Stat(ctx context.Context, key string) (*ObjectInfo, error
 		if errors.Is(err, fs.ErrorObjectNotFound) {
 			return nil, ErrNotFound
 		}
+
 		if errors.Is(err, fs.ErrorDirNotFound) {
 			return nil, ErrNotFound
 		}
+
 		return nil, fmt.Errorf("getting object: %w", err)
 	}
 
@@ -142,13 +151,16 @@ func (r *RcloneStorer) Delete(ctx context.Context, key string) error {
 		if errors.Is(err, fs.ErrorObjectNotFound) {
 			return nil // Match S3 behavior: no error if doesn't exist
 		}
+
 		if errors.Is(err, fs.ErrorDirNotFound) {
 			return nil
 		}
+
 		return fmt.Errorf("getting object: %w", err)
 	}
 
-	if err := obj.Remove(ctx); err != nil {
+	err = obj.Remove(ctx)
+	if err != nil {
 		return fmt.Errorf("removing object: %w", err)
 	}
 
@@ -173,7 +185,9 @@ func (r *RcloneStorer) List(ctx context.Context, prefix string) ([]string, error
 }
 
 // ListStream returns a channel of ObjectInfo for large result sets.
-func (r *RcloneStorer) ListStream(ctx context.Context, prefix string) <-chan ObjectInfo {
+func (r *RcloneStorer) ListStream(
+	ctx context.Context, prefix string,
+) <-chan ObjectInfo {
 	ch := make(chan ObjectInfo)
 
 	go func() {
@@ -204,13 +218,14 @@ func (r *RcloneStorer) ListStream(ctx context.Context, prefix string) <-chan Obj
 }
 
 // Info returns human-readable storage location information.
-func (r *RcloneStorer) Info() StorageInfo {
+func (r *RcloneStorer) Info() Info {
 	location := r.remote
 	if r.path != "" {
 		location += ":" + r.path
 	}
-	return StorageInfo{
-		Type:     "rclone",
+
+	return Info{
+		Type:     schemeRclone,
 		Location: location,
 	}
 }
@@ -227,10 +242,12 @@ func (pr *progressReader) Read(p []byte) (int, error) {
 	if n > 0 {
 		pr.read += int64(n)
 		if pr.callback != nil {
-			if callbackErr := pr.callback(pr.read); callbackErr != nil {
+			callbackErr := pr.callback(pr.read)
+			if callbackErr != nil {
 				return n, callbackErr
 			}
 		}
 	}
+
 	return n, err
 }

internal/storage/s3.go

@@ -24,12 +24,16 @@ func (s *S3Storer) Put(ctx context.Context, key string, data io.Reader) error {
 }
 
 // PutWithProgress stores data with progress reporting.
-func (s *S3Storer) PutWithProgress(ctx context.Context, key string, data io.Reader, size int64, progress ProgressCallback) error {
+func (s *S3Storer) PutWithProgress(
+	ctx context.Context, key string, data io.Reader,
+	size int64, progress ProgressCallback,
+) error {
 	// Convert storage.ProgressCallback to s3.ProgressCallback
 	var s3Progress s3.ProgressCallback
 	if progress != nil {
 		s3Progress = s3.ProgressCallback(progress)
 	}
+
 	return s.client.PutObjectWithProgress(ctx, key, data, size, s3Progress)
 }
 
@@ -44,6 +48,7 @@ func (s *S3Storer) Stat(ctx context.Context, key string) (*ObjectInfo, error) {
 	if err != nil {
 		return nil, err
 	}
+
 	return &ObjectInfo{
 		Key:  info.Key,
 		Size: info.Size,
@@ -65,6 +70,7 @@ func (s *S3Storer) ListStream(ctx context.Context, prefix string) <-chan ObjectI
 	ch := make(chan ObjectInfo)
 	go func() {
 		defer close(ch)
+
 		for info := range s.client.ListObjectsStream(ctx, prefix, false) {
 			ch <- ObjectInfo{
 				Key:  info.Key,
@@ -73,12 +79,13 @@ func (s *S3Storer) ListStream(ctx context.Context, prefix string) <-chan ObjectI
 			}
 		}
 	}()
+
 	return ch
 }
 
 // Info returns human-readable storage location information.
-func (s *S3Storer) Info() StorageInfo {
-	return StorageInfo{
+func (s *S3Storer) Info() Info {
+	return Info{
 		Type:     "s3",
 		Location: fmt.Sprintf("%s/%s", s.client.Endpoint(), s.client.BucketName()),
 	}

internal/storage/storer.go

@@ -30,14 +30,15 @@ type ObjectInfo struct {
 	Err  error  // Error for streaming results (nil on success)
 }
 
-// StorageInfo provides human-readable storage configuration.
-type StorageInfo struct {
+// Info provides human-readable storage configuration.
+type Info struct {
 	Type     string // "s3" or "file"
 	Location string // endpoint/bucket for S3, base path for filesystem
 }
 
 // Storer defines the interface for storage backends.
-// All paths are relative to the storage root (bucket/prefix for S3, base directory for filesystem).
+// All paths are relative to the storage root (bucket/prefix for S3, base
+// directory for filesystem).
 type Storer interface {
 	// Put stores data at the specified key.
 	// Parent directories are created automatically for filesystem backends.
@@ -46,7 +47,8 @@ type Storer interface {
 	// PutWithProgress stores data with progress reporting.
 	// Size must be the exact size of the data to store.
 	// The progress callback is called periodically with bytes transferred.
-	PutWithProgress(ctx context.Context, key string, data io.Reader, size int64, progress ProgressCallback) error
+	PutWithProgress(ctx context.Context, key string, data io.Reader,
+		size int64, progress ProgressCallback) error
 
 	// Get retrieves data from the specified key.
 	// The caller must close the returned ReadCloser.
@@ -70,5 +72,5 @@ type Storer interface {
 	ListStream(ctx context.Context, prefix string) <-chan ObjectInfo
 
 	// Info returns human-readable storage location information.
-	Info() StorageInfo
+	Info() Info
 }