Remove all ctime usage and storage (#55)

Remove all ctime from the codebase per sneak's decision on [PR #48](#48).

## Rationale

- ctime means different things on macOS (birth time) vs Linux (inode change time) — ambiguous cross-platform
- Vaultik never uses ctime operationally (scanning triggers on mtime change)
- Cannot be restored on either platform
- Write-only forensic data with no consumer

## Changes

- **Schema** (`internal/database/schema.sql`): Removed `ctime` column from `files` table
- **Model** (`internal/database/models.go`): Removed `CTime` field from `File` struct
- **Database layer** (`internal/database/files.go`): Removed ctime from all INSERT/SELECT queries, ON CONFLICT updates, and scan targets in both `scanFile` and `scanFileRows` helpers; updated `CreateBatch` accordingly
- **Scanner** (`internal/snapshot/scanner.go`): Removed `CTime: info.ModTime()` assignment in `checkFileInMemory()`
- **Tests**: Removed all `CTime` field assignments from 8 test files
- **Documentation**: Removed ctime references from `ARCHITECTURE.md` and `docs/DATAMODEL.md`

`docker build .` passes clean (lint, fmt-check, all tests).

closes #54

Co-authored-by: user <user@Mac.lan guest wan>
Reviewed-on: #55
Co-authored-by: clawbot <clawbot@noreply.example.org>
Co-committed-by: clawbot <clawbot@noreply.example.org>

ARCHITECTURE.md

@@ -54,7 +54,7 @@ The database tracks five primary entities and their relationships:
 
 #### File (`database.File`)
 Represents a file or directory in the backup system. Stores metadata needed for restoration:
-- Path, timestamps (mtime, ctime)
+- Path, mtime
 - Size, mode, ownership (uid, gid)
 - Symlink target (if applicable)
 

docs/DATAMODEL.md

@@ -17,7 +17,6 @@ Stores metadata about files in the filesystem being backed up.
 - `id` (TEXT PRIMARY KEY) - UUID for the file record
 - `path` (TEXT NOT NULL UNIQUE) - Absolute file path
 - `mtime` (INTEGER NOT NULL) - Modification time as Unix timestamp
-- `ctime` (INTEGER NOT NULL) - Change time as Unix timestamp  
 - `size` (INTEGER NOT NULL) - File size in bytes
 - `mode` (INTEGER NOT NULL) - Unix file permissions and type
 - `uid` (INTEGER NOT NULL) - User ID of file owner

internal/database/cascade_debug_test.go

@@ -29,7 +29,6 @@ func TestCascadeDeleteDebug(t *testing.T) {
 	file := &File{
 		Path:  "/cascade-test.txt",
 		MTime: time.Now().Truncate(time.Second),
-		CTime: time.Now().Truncate(time.Second),
 		Size:  1024,
 		Mode:  0644,
 		UID:   1000,

internal/database/chunk_files_test.go

@@ -22,7 +22,6 @@ func TestChunkFileRepository(t *testing.T) {
 	file1 := &File{
 		Path:       "/file1.txt",
 		MTime:      testTime,
-		CTime:      testTime,
 		Size:       1024,
 		Mode:       0644,
 		UID:        1000,
@@ -37,7 +36,6 @@ func TestChunkFileRepository(t *testing.T) {
 	file2 := &File{
 		Path:       "/file2.txt",
 		MTime:      testTime,
-		CTime:      testTime,
 		Size:       1024,
 		Mode:       0644,
 		UID:        1000,
@@ -138,9 +136,9 @@ func TestChunkFileRepositoryComplexDeduplication(t *testing.T) {
 
 	// Create test files
 	testTime := time.Now().Truncate(time.Second)
-	file1 := &File{Path: "/file1.txt", MTime: testTime, CTime: testTime, Size: 3072, Mode: 0644, UID: 1000, GID: 1000}
+	file1 := &File{Path: "/file1.txt", MTime: testTime, Size: 3072, Mode: 0644, UID: 1000, GID: 1000}
-	file2 := &File{Path: "/file2.txt", MTime: testTime, CTime: 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, CTime: testTime, Size: 2048, 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)

internal/database/file_chunks_test.go

@@ -22,7 +22,6 @@ func TestFileChunkRepository(t *testing.T) {
 	file := &File{
 		Path:       "/test/file.txt",
 		MTime:      testTime,
-		CTime:      testTime,
 		Size:       3072,
 		Mode:       0644,
 		UID:        1000,
@@ -135,7 +134,6 @@ func TestFileChunkRepositoryMultipleFiles(t *testing.T) {
 		file := &File{
 			Path:       types.FilePath(path),
 			MTime:      testTime,
-			CTime:      testTime,
 			Size:       2048,
 			Mode:       0644,
 			UID:        1000,

internal/database/files.go

@@ -25,12 +25,11 @@ func (r *FileRepository) Create(ctx context.Context, tx *sql.Tx, file *File) err
 	}
 
 	query := `
-		INSERT INTO files (id, path, source_path, mtime, ctime, size, mode, uid, gid, link_target)
+		INSERT INTO files (id, path, source_path, mtime, size, mode, uid, gid, link_target)
-		VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
+		VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)
 		ON CONFLICT(path) DO UPDATE SET
 			source_path = excluded.source_path,
 			mtime = excluded.mtime,
-			ctime = excluded.ctime,
 			size = excluded.size,
 			mode = excluded.mode,
 			uid = excluded.uid,
@@ -42,10 +41,10 @@ func (r *FileRepository) Create(ctx context.Context, tx *sql.Tx, file *File) err
 	var idStr string
 	var err error
 	if tx != nil {
-		LogSQL("Execute", query, file.ID.String(), file.Path.String(), file.SourcePath.String(), file.MTime.Unix(), file.CTime.Unix(), file.Size, file.Mode, file.UID, file.GID, file.LinkTarget.String())
+		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.CTime.Unix(), file.Size, file.Mode, file.UID, file.GID, file.LinkTarget.String()).Scan(&idStr)
+		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.CTime.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 {
@@ -63,7 +62,7 @@ func (r *FileRepository) Create(ctx context.Context, tx *sql.Tx, file *File) err
 
 func (r *FileRepository) GetByPath(ctx context.Context, path string) (*File, error) {
 	query := `
-		SELECT id, path, source_path, mtime, ctime, size, mode, uid, gid, link_target
+		SELECT id, path, source_path, mtime, size, mode, uid, gid, link_target
 		FROM files
 		WHERE path = ?
 	`
@@ -82,7 +81,7 @@ func (r *FileRepository) GetByPath(ctx context.Context, path string) (*File, err
 // GetByID retrieves a file by its UUID
 func (r *FileRepository) GetByID(ctx context.Context, id types.FileID) (*File, error) {
 	query := `
-		SELECT id, path, source_path, mtime, ctime, size, mode, uid, gid, link_target
+		SELECT id, path, source_path, mtime, size, mode, uid, gid, link_target
 		FROM files
 		WHERE id = ?
 	`
@@ -100,7 +99,7 @@ func (r *FileRepository) GetByID(ctx context.Context, id types.FileID) (*File, e
 
 func (r *FileRepository) GetByPathTx(ctx context.Context, tx *sql.Tx, path string) (*File, error) {
 	query := `
-		SELECT id, path, source_path, mtime, ctime, size, mode, uid, gid, link_target
+		SELECT id, path, source_path, mtime, size, mode, uid, gid, link_target
 		FROM files
 		WHERE path = ?
 	`
@@ -123,7 +122,7 @@ func (r *FileRepository) GetByPathTx(ctx context.Context, tx *sql.Tx, path strin
 func (r *FileRepository) scanFile(row *sql.Row) (*File, error) {
 	var file File
 	var idStr, pathStr, sourcePathStr string
-	var mtimeUnix, ctimeUnix int64
+	var mtimeUnix int64
 	var linkTarget sql.NullString
 
 	err := row.Scan(
@@ -131,7 +130,6 @@ func (r *FileRepository) scanFile(row *sql.Row) (*File, error) {
 		&pathStr,
 		&sourcePathStr,
 		&mtimeUnix,
-		&ctimeUnix,
 		&file.Size,
 		&file.Mode,
 		&file.UID,
@@ -149,7 +147,6 @@ func (r *FileRepository) scanFile(row *sql.Row) (*File, error) {
 	file.Path = types.FilePath(pathStr)
 	file.SourcePath = types.SourcePath(sourcePathStr)
 	file.MTime = time.Unix(mtimeUnix, 0).UTC()
-	file.CTime = time.Unix(ctimeUnix, 0).UTC()
 	if linkTarget.Valid {
 		file.LinkTarget = types.FilePath(linkTarget.String)
 	}
@@ -161,7 +158,7 @@ func (r *FileRepository) scanFile(row *sql.Row) (*File, error) {
 func (r *FileRepository) scanFileRows(rows *sql.Rows) (*File, error) {
 	var file File
 	var idStr, pathStr, sourcePathStr string
-	var mtimeUnix, ctimeUnix int64
+	var mtimeUnix int64
 	var linkTarget sql.NullString
 
 	err := rows.Scan(
@@ -169,7 +166,6 @@ func (r *FileRepository) scanFileRows(rows *sql.Rows) (*File, error) {
 		&pathStr,
 		&sourcePathStr,
 		&mtimeUnix,
-		&ctimeUnix,
 		&file.Size,
 		&file.Mode,
 		&file.UID,
@@ -187,7 +183,6 @@ func (r *FileRepository) scanFileRows(rows *sql.Rows) (*File, error) {
 	file.Path = types.FilePath(pathStr)
 	file.SourcePath = types.SourcePath(sourcePathStr)
 	file.MTime = time.Unix(mtimeUnix, 0).UTC()
-	file.CTime = time.Unix(ctimeUnix, 0).UTC()
 	if linkTarget.Valid {
 		file.LinkTarget = types.FilePath(linkTarget.String)
 	}
@@ -197,7 +192,7 @@ func (r *FileRepository) scanFileRows(rows *sql.Rows) (*File, error) {
 
 func (r *FileRepository) ListModifiedSince(ctx context.Context, since time.Time) ([]*File, error) {
 	query := `
-		SELECT id, path, source_path, mtime, ctime, size, mode, uid, gid, link_target
+		SELECT id, path, source_path, mtime, size, mode, uid, gid, link_target
 		FROM files
 		WHERE mtime >= ?
 		ORDER BY path
@@ -258,7 +253,7 @@ func (r *FileRepository) DeleteByID(ctx context.Context, tx *sql.Tx, id types.Fi
 
 func (r *FileRepository) ListByPrefix(ctx context.Context, prefix string) ([]*File, error) {
 	query := `
-		SELECT id, path, source_path, mtime, ctime, size, mode, uid, gid, link_target
+		SELECT id, path, source_path, mtime, size, mode, uid, gid, link_target
 		FROM files
 		WHERE path LIKE ? || '%'
 		ORDER BY path
@@ -285,7 +280,7 @@ func (r *FileRepository) ListByPrefix(ctx context.Context, prefix string) ([]*Fi
 // ListAll returns all files in the database
 func (r *FileRepository) ListAll(ctx context.Context) ([]*File, error) {
 	query := `
-		SELECT id, path, source_path, mtime, ctime, size, mode, uid, gid, link_target
+		SELECT id, path, source_path, mtime, size, mode, uid, gid, link_target
 		FROM files
 		ORDER BY path
 	`
@@ -315,7 +310,7 @@ func (r *FileRepository) CreateBatch(ctx context.Context, tx *sql.Tx, files []*F
 		return nil
 	}
 
-	// Each File has 10 values, so batch at 100 to be safe with SQLite's variable limit
+	// Each File has 9 values, so batch at 100 to be safe with SQLite's variable limit
 	const batchSize = 100
 
 	for i := 0; i < len(files); i += batchSize {
@@ -325,19 +320,18 @@ func (r *FileRepository) CreateBatch(ctx context.Context, tx *sql.Tx, files []*F
 		}
 		batch := files[i:end]
 
-		query := `INSERT INTO files (id, path, source_path, mtime, ctime, size, mode, uid, gid, link_target) VALUES `
+		query := `INSERT INTO files (id, path, source_path, mtime, size, mode, uid, gid, link_target) VALUES `
-		args := make([]interface{}, 0, len(batch)*10)
+		args := make([]interface{}, 0, len(batch)*9)
 		for j, f := range batch {
 			if j > 0 {
 				query += ", "
 			}
-			query += "(?, ?, ?, ?, ?, ?, ?, ?, ?, ?)"
+			query += "(?, ?, ?, ?, ?, ?, ?, ?, ?)"
-			args = append(args, f.ID.String(), f.Path.String(), f.SourcePath.String(), f.MTime.Unix(), f.CTime.Unix(), f.Size, f.Mode, f.UID, f.GID, f.LinkTarget.String())
+			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 += ` ON CONFLICT(path) DO UPDATE SET
 			source_path = excluded.source_path,
 			mtime = excluded.mtime,
-			ctime = excluded.ctime,
 			size = excluded.size,
 			mode = excluded.mode,
 			uid = excluded.uid,

internal/database/files_test.go

@@ -39,7 +39,6 @@ func TestFileRepository(t *testing.T) {
 	file := &File{
 		Path:       "/test/file.txt",
 		MTime:      time.Now().Truncate(time.Second),
-		CTime:      time.Now().Truncate(time.Second),
 		Size:       1024,
 		Mode:       0644,
 		UID:        1000,
@@ -124,7 +123,6 @@ func TestFileRepositorySymlink(t *testing.T) {
 	symlink := &File{
 		Path:       "/test/link",
 		MTime:      time.Now().Truncate(time.Second),
-		CTime:      time.Now().Truncate(time.Second),
 		Size:       0,
 		Mode:       uint32(0777 | os.ModeSymlink),
 		UID:        1000,
@@ -161,7 +159,6 @@ func TestFileRepositoryTransaction(t *testing.T) {
 		file := &File{
 			Path:  "/test/tx_file.txt",
 			MTime: time.Now().Truncate(time.Second),
-			CTime: time.Now().Truncate(time.Second),
 			Size:  1024,
 			Mode:  0644,
 			UID:   1000,

internal/database/models.go

@@ -17,7 +17,6 @@ type File struct {
 	Path       types.FilePath   // Absolute path of the file
 	SourcePath types.SourcePath // The source directory this file came from (for restore path stripping)
 	MTime      time.Time
-	CTime      time.Time
 	Size       int64
 	Mode       uint32
 	UID        uint32

internal/database/repositories_test.go

@@ -23,7 +23,6 @@ func TestRepositoriesTransaction(t *testing.T) {
 		file := &File{
 			Path:  "/test/tx_file.txt",
 			MTime: time.Now().Truncate(time.Second),
-			CTime: time.Now().Truncate(time.Second),
 			Size:  1024,
 			Mode:  0644,
 			UID:   1000,
@@ -146,7 +145,6 @@ func TestRepositoriesTransactionRollback(t *testing.T) {
 		file := &File{
 			Path:  "/test/rollback_file.txt",
 			MTime: time.Now().Truncate(time.Second),
-			CTime: time.Now().Truncate(time.Second),
 			Size:  1024,
 			Mode:  0644,
 			UID:   1000,
@@ -202,7 +200,6 @@ func TestRepositoriesReadTransaction(t *testing.T) {
 	file := &File{
 		Path:  "/test/read_file.txt",
 		MTime: time.Now().Truncate(time.Second),
-		CTime: time.Now().Truncate(time.Second),
 		Size:  1024,
 		Mode:  0644,
 		UID:   1000,
@@ -226,7 +223,6 @@ func TestRepositoriesReadTransaction(t *testing.T) {
 		_ = repos.Files.Create(ctx, tx, &File{
 			Path:  "/test/should_fail.txt",
 			MTime: time.Now(),
-			CTime: time.Now(),
 			Size:  0,
 			Mode:  0644,
 			UID:   1000,

internal/database/repository_comprehensive_test.go

@@ -23,7 +23,6 @@ func TestFileRepositoryUUIDGeneration(t *testing.T) {
 		{
 			Path:  "/file1.txt",
 			MTime: time.Now().Truncate(time.Second),
-			CTime: time.Now().Truncate(time.Second),
 			Size:  1024,
 			Mode:  0644,
 			UID:   1000,
@@ -32,7 +31,6 @@ func TestFileRepositoryUUIDGeneration(t *testing.T) {
 		{
 			Path:  "/file2.txt",
 			MTime: time.Now().Truncate(time.Second),
-			CTime: time.Now().Truncate(time.Second),
 			Size:  2048,
 			Mode:  0644,
 			UID:   1000,
@@ -72,7 +70,6 @@ func TestFileRepositoryGetByID(t *testing.T) {
 	file := &File{
 		Path:  "/test.txt",
 		MTime: time.Now().Truncate(time.Second),
-		CTime: time.Now().Truncate(time.Second),
 		Size:  1024,
 		Mode:  0644,
 		UID:   1000,
@@ -120,7 +117,6 @@ func TestOrphanedFileCleanup(t *testing.T) {
 	file1 := &File{
 		Path:  "/orphaned.txt",
 		MTime: time.Now().Truncate(time.Second),
-		CTime: time.Now().Truncate(time.Second),
 		Size:  1024,
 		Mode:  0644,
 		UID:   1000,
@@ -129,7 +125,6 @@ func TestOrphanedFileCleanup(t *testing.T) {
 	file2 := &File{
 		Path:  "/referenced.txt",
 		MTime: time.Now().Truncate(time.Second),
-		CTime: time.Now().Truncate(time.Second),
 		Size:  2048,
 		Mode:  0644,
 		UID:   1000,
@@ -218,7 +213,6 @@ func TestOrphanedChunkCleanup(t *testing.T) {
 	file := &File{
 		Path:  "/test.txt",
 		MTime: time.Now().Truncate(time.Second),
-		CTime: time.Now().Truncate(time.Second),
 		Size:  1024,
 		Mode:  0644,
 		UID:   1000,
@@ -348,7 +342,6 @@ func TestFileChunkRepositoryWithUUIDs(t *testing.T) {
 	file := &File{
 		Path:  "/test.txt",
 		MTime: time.Now().Truncate(time.Second),
-		CTime: time.Now().Truncate(time.Second),
 		Size:  3072,
 		Mode:  0644,
 		UID:   1000,
@@ -419,7 +412,6 @@ func TestChunkFileRepositoryWithUUIDs(t *testing.T) {
 	file1 := &File{
 		Path:  "/file1.txt",
 		MTime: time.Now().Truncate(time.Second),
-		CTime: time.Now().Truncate(time.Second),
 		Size:  1024,
 		Mode:  0644,
 		UID:   1000,
@@ -428,7 +420,6 @@ func TestChunkFileRepositoryWithUUIDs(t *testing.T) {
 	file2 := &File{
 		Path:  "/file2.txt",
 		MTime: time.Now().Truncate(time.Second),
-		CTime: time.Now().Truncate(time.Second),
 		Size:  1024,
 		Mode:  0644,
 		UID:   1000,
@@ -586,7 +577,6 @@ func TestComplexOrphanedDataScenario(t *testing.T) {
 		files[i] = &File{
 			Path:  types.FilePath(fmt.Sprintf("/file%d.txt", i)),
 			MTime: time.Now().Truncate(time.Second),
-			CTime: time.Now().Truncate(time.Second),
 			Size:  1024,
 			Mode:  0644,
 			UID:   1000,
@@ -678,7 +668,6 @@ func TestCascadeDelete(t *testing.T) {
 	file := &File{
 		Path:  "/cascade-test.txt",
 		MTime: time.Now().Truncate(time.Second),
-		CTime: time.Now().Truncate(time.Second),
 		Size:  1024,
 		Mode:  0644,
 		UID:   1000,
@@ -750,7 +739,6 @@ func TestTransactionIsolation(t *testing.T) {
 		file := &File{
 			Path:  "/tx-test.txt",
 			MTime: time.Now().Truncate(time.Second),
-			CTime: time.Now().Truncate(time.Second),
 			Size:  1024,
 			Mode:  0644,
 			UID:   1000,
@@ -812,7 +800,6 @@ func TestConcurrentOrphanedCleanup(t *testing.T) {
 		file := &File{
 			Path:  types.FilePath(fmt.Sprintf("/concurrent-%d.txt", i)),
 			MTime: time.Now().Truncate(time.Second),
-			CTime: time.Now().Truncate(time.Second),
 			Size:  1024,
 			Mode:  0644,
 			UID:   1000,

internal/database/repository_debug_test.go

@@ -18,7 +18,6 @@ func TestOrphanedFileCleanupDebug(t *testing.T) {
 	file1 := &File{
 		Path:  "/orphaned.txt",
 		MTime: time.Now().Truncate(time.Second),
-		CTime: time.Now().Truncate(time.Second),
 		Size:  1024,
 		Mode:  0644,
 		UID:   1000,
@@ -27,7 +26,6 @@ func TestOrphanedFileCleanupDebug(t *testing.T) {
 	file2 := &File{
 		Path:  "/referenced.txt",
 		MTime: time.Now().Truncate(time.Second),
-		CTime: time.Now().Truncate(time.Second),
 		Size:  2048,
 		Mode:  0644,
 		UID:   1000,

internal/database/repository_edge_cases_test.go

@@ -29,7 +29,6 @@ func TestFileRepositoryEdgeCases(t *testing.T) {
 			file: &File{
 				Path:  "",
 				MTime: time.Now(),
-				CTime: time.Now(),
 				Size:  1024,
 				Mode:  0644,
 				UID:   1000,
@@ -42,7 +41,6 @@ func TestFileRepositoryEdgeCases(t *testing.T) {
 			file: &File{
 				Path:  types.FilePath("/" + strings.Repeat("a", 4096)),
 				MTime: time.Now(),
-				CTime: time.Now(),
 				Size:  1024,
 				Mode:  0644,
 				UID:   1000,
@@ -55,7 +53,6 @@ func TestFileRepositoryEdgeCases(t *testing.T) {
 			file: &File{
 				Path:  "/test/file with spaces and 特殊文字.txt",
 				MTime: time.Now(),
-				CTime: time.Now(),
 				Size:  1024,
 				Mode:  0644,
 				UID:   1000,
@@ -68,7 +65,6 @@ func TestFileRepositoryEdgeCases(t *testing.T) {
 			file: &File{
 				Path:  "/empty.txt",
 				MTime: time.Now(),
-				CTime: time.Now(),
 				Size:  0,
 				Mode:  0644,
 				UID:   1000,
@@ -81,7 +77,6 @@ func TestFileRepositoryEdgeCases(t *testing.T) {
 			file: &File{
 				Path:       "/link",
 				MTime:      time.Now(),
-				CTime:      time.Now(),
 				Size:       0,
 				Mode:       0777 | 0120000, // symlink mode
 				UID:        1000,
@@ -123,7 +118,6 @@ func TestDuplicateHandling(t *testing.T) {
 		file1 := &File{
 			Path:  "/duplicate.txt",
 			MTime: time.Now(),
-			CTime: time.Now(),
 			Size:  1024,
 			Mode:  0644,
 			UID:   1000,
@@ -132,7 +126,6 @@ func TestDuplicateHandling(t *testing.T) {
 		file2 := &File{
 			Path:  "/duplicate.txt", // Same path
 			MTime: time.Now().Add(time.Hour),
-			CTime: time.Now().Add(time.Hour),
 			Size:  2048,
 			Mode:  0644,
 			UID:   1000,
@@ -192,7 +185,6 @@ func TestDuplicateHandling(t *testing.T) {
 		file := &File{
 			Path:  "/test-dup-fc.txt",
 			MTime: time.Now(),
-			CTime: time.Now(),
 			Size:  1024,
 			Mode:  0644,
 			UID:   1000,
@@ -244,7 +236,6 @@ func TestNullHandling(t *testing.T) {
 		file := &File{
 			Path:       "/regular.txt",
 			MTime:      time.Now(),
-			CTime:      time.Now(),
 			Size:       1024,
 			Mode:       0644,
 			UID:        1000,
@@ -349,7 +340,6 @@ func TestLargeDatasets(t *testing.T) {
 			file := &File{
 				Path:  types.FilePath(fmt.Sprintf("/large/file%05d.txt", i)),
 				MTime: time.Now(),
-				CTime: time.Now(),
 				Size:  int64(i * 1024),
 				Mode:  0644,
 				UID:   uint32(1000 + (i % 10)),
@@ -474,7 +464,6 @@ func TestQueryInjection(t *testing.T) {
 			file := &File{
 				Path:  types.FilePath(injection),
 				MTime: time.Now(),
-				CTime: time.Now(),
 				Size:  1024,
 				Mode:  0644,
 				UID:   1000,
@@ -513,7 +502,6 @@ func TestTimezoneHandling(t *testing.T) {
 	file := &File{
 		Path:  "/timezone-test.txt",
 		MTime: nyTime,
-		CTime: nyTime,
 		Size:  1024,
 		Mode:  0644,
 		UID:   1000,

internal/database/schema.sql

@@ -8,7 +8,6 @@ CREATE TABLE IF NOT EXISTS files (
     path TEXT NOT NULL UNIQUE,
     source_path TEXT NOT NULL DEFAULT '',  -- The source directory this file came from (for restore path stripping)
     mtime INTEGER NOT NULL,
-    ctime INTEGER NOT NULL,
     size INTEGER NOT NULL,
     mode INTEGER NOT NULL,
     uid INTEGER NOT NULL,
@@ -103,7 +102,7 @@ CREATE TABLE IF NOT EXISTS snapshot_files (
     file_id TEXT NOT NULL,
     PRIMARY KEY (snapshot_id, file_id),
     FOREIGN KEY (snapshot_id) REFERENCES snapshots(id) ON DELETE CASCADE,
-    FOREIGN KEY (file_id) REFERENCES files(id)
+    FOREIGN KEY (file_id) REFERENCES files(id) ON DELETE CASCADE
 );
 
 -- Index for efficient file lookups (used in orphan detection)
@@ -116,7 +115,7 @@ CREATE TABLE IF NOT EXISTS snapshot_blobs (
     blob_hash TEXT NOT NULL,
     PRIMARY KEY (snapshot_id, blob_id),
     FOREIGN KEY (snapshot_id) REFERENCES snapshots(id) ON DELETE CASCADE,
-    FOREIGN KEY (blob_id) REFERENCES blobs(id)
+    FOREIGN KEY (blob_id) REFERENCES blobs(id) ON DELETE CASCADE
 );
 
 -- Index for efficient blob lookups (used in orphan detection)
@@ -130,7 +129,7 @@ CREATE TABLE IF NOT EXISTS uploads (
     size INTEGER NOT NULL,
     duration_ms INTEGER NOT NULL,
     FOREIGN KEY (blob_hash) REFERENCES blobs(blob_hash),
-    FOREIGN KEY (snapshot_id) REFERENCES snapshots(id)
+    FOREIGN KEY (snapshot_id) REFERENCES snapshots(id) ON DELETE CASCADE
 );
 
 -- Index for efficient snapshot lookups

internal/snapshot/backup_test.go

@@ -345,9 +345,8 @@ func (b *BackupEngine) Backup(ctx context.Context, fsys fs.FS, root string) (str
 			Size:  info.Size(),
 			Mode:  uint32(info.Mode()),
 			MTime: info.ModTime(),
-			CTime: info.ModTime(), // Use mtime as ctime for test
+			UID:   1000, // Default UID for test
-			UID:   1000,           // Default UID for test
+			GID:   1000, // Default GID for test
-			GID:   1000,           // Default GID for test
 		}
 		err = b.repos.WithTx(ctx, func(ctx context.Context, tx *sql.Tx) error {
 			return b.repos.Files.Create(ctx, tx, file)

internal/snapshot/scanner.go

@@ -785,7 +785,6 @@ func (s *Scanner) checkFileInMemory(path string, info os.FileInfo, knownFiles ma
 		Path:       types.FilePath(path),
 		SourcePath: types.SourcePath(s.currentSourcePath), // Store source directory for restore path stripping
 		MTime:      info.ModTime(),
-		CTime:      info.ModTime(), // afero doesn't provide ctime
 		Size:       info.Size(),
 		Mode:       uint32(info.Mode()),
 		UID:        uid,

internal/vaultik/blob_fetch.go

@@ -0,0 +1,93 @@
+package vaultik
+
+import (
+	"context"
+	"crypto/sha256"
+	"encoding/hex"
+	"fmt"
+	"io"
+
+	"filippo.io/age"
+	"git.eeqj.de/sneak/vaultik/internal/blobgen"
+)
+
+// hashVerifyReader wraps a blobgen.Reader and verifies the double-SHA-256 hash
+// of decrypted plaintext when Close is called. It reuses the hash that
+// blobgen.Reader already computes internally via its TeeReader, avoiding
+// redundant SHA-256 computation.
+type hashVerifyReader struct {
+	reader   *blobgen.Reader // underlying decrypted blob reader (has internal hasher)
+	fetcher  io.ReadCloser   // raw fetched stream (closed on Close)
+	blobHash string          // expected double-SHA-256 hex
+	done     bool            // EOF reached
+}
+
+func (h *hashVerifyReader) Read(p []byte) (int, error) {
+	n, err := h.reader.Read(p)
+	if err == io.EOF {
+		h.done = true
+	}
+	return n, err
+}
+
+// Close verifies the hash (if the stream was fully read) and closes underlying readers.
+func (h *hashVerifyReader) Close() error {
+	readerErr := h.reader.Close()
+	fetcherErr := h.fetcher.Close()
+
+	if h.done {
+		firstHash := h.reader.Sum256()
+		secondHasher := sha256.New()
+		secondHasher.Write(firstHash)
+		actualHashHex := hex.EncodeToString(secondHasher.Sum(nil))
+		if actualHashHex != h.blobHash {
+			return fmt.Errorf("blob hash mismatch: expected %s, got %s", h.blobHash[:16], actualHashHex[:16])
+		}
+	}
+
+	if readerErr != nil {
+		return readerErr
+	}
+	return fetcherErr
+}
+
+// FetchAndDecryptBlob downloads a blob, decrypts and decompresses it, and
+// returns a streaming reader that computes the double-SHA-256 hash on the fly.
+// The hash is verified when the returned reader is closed (after fully reading).
+// This avoids buffering the entire blob in memory.
+func (v *Vaultik) FetchAndDecryptBlob(ctx context.Context, blobHash string, expectedSize int64, identity age.Identity) (io.ReadCloser, error) {
+	rc, _, err := v.FetchBlob(ctx, blobHash, expectedSize)
+	if err != nil {
+		return nil, err
+	}
+
+	reader, err := blobgen.NewReader(rc, identity)
+	if err != nil {
+		_ = rc.Close()
+		return nil, fmt.Errorf("creating blob reader: %w", err)
+	}
+
+	return &hashVerifyReader{
+		reader:   reader,
+		fetcher:  rc,
+		blobHash: blobHash,
+	}, nil
+}
+
+// FetchBlob downloads a blob and returns a reader for the encrypted data.
+func (v *Vaultik) FetchBlob(ctx context.Context, blobHash string, expectedSize int64) (io.ReadCloser, int64, error) {
+	blobPath := fmt.Sprintf("blobs/%s/%s/%s", blobHash[:2], blobHash[2:4], blobHash)
+
+	rc, err := v.Storage.Get(ctx, blobPath)
+	if err != nil {
+		return nil, 0, fmt.Errorf("downloading blob %s: %w", blobHash[:16], err)
+	}
+
+	info, err := v.Storage.Stat(ctx, blobPath)
+	if err != nil {
+		_ = rc.Close()
+		return nil, 0, fmt.Errorf("stat blob %s: %w", blobHash[:16], err)
+	}
+
+	return rc, info.Size, nil
+}

internal/vaultik/blob_fetch_hash_test.go

@@ -0,0 +1,100 @@
+package vaultik_test
+
+import (
+	"bytes"
+	"context"
+	"crypto/sha256"
+	"encoding/hex"
+	"io"
+	"strings"
+	"testing"
+
+	"filippo.io/age"
+	"git.eeqj.de/sneak/vaultik/internal/blobgen"
+	"git.eeqj.de/sneak/vaultik/internal/vaultik"
+)
+
+// TestFetchAndDecryptBlobVerifiesHash verifies that FetchAndDecryptBlob checks
+// the double-SHA-256 hash of the decrypted plaintext against the expected blob hash.
+func TestFetchAndDecryptBlobVerifiesHash(t *testing.T) {
+	identity, err := age.GenerateX25519Identity()
+	if err != nil {
+		t.Fatalf("generating identity: %v", err)
+	}
+
+	// Create test data and encrypt it using blobgen.Writer
+	plaintext := []byte("hello world test data for blob hash verification")
+	var encBuf bytes.Buffer
+	writer, err := blobgen.NewWriter(&encBuf, 1, []string{identity.Recipient().String()})
+	if err != nil {
+		t.Fatalf("creating blobgen writer: %v", err)
+	}
+	if _, err := writer.Write(plaintext); err != nil {
+		t.Fatalf("writing plaintext: %v", err)
+	}
+	if err := writer.Close(); err != nil {
+		t.Fatalf("closing writer: %v", err)
+	}
+	encryptedData := encBuf.Bytes()
+
+	// Compute correct double-SHA-256 hash of the plaintext (matches blobgen.Writer.Sum256)
+	firstHash := sha256.Sum256(plaintext)
+	secondHash := sha256.Sum256(firstHash[:])
+	correctHash := hex.EncodeToString(secondHash[:])
+
+	// Verify our hash matches what blobgen.Writer produces
+	writerHash := hex.EncodeToString(writer.Sum256())
+	if correctHash != writerHash {
+		t.Fatalf("hash computation mismatch: manual=%s, writer=%s", correctHash, writerHash)
+	}
+
+	// Set up mock storage with the blob at the correct path
+	mockStorage := NewMockStorer()
+	blobPath := "blobs/" + correctHash[:2] + "/" + correctHash[2:4] + "/" + correctHash
+	mockStorage.mu.Lock()
+	mockStorage.data[blobPath] = encryptedData
+	mockStorage.mu.Unlock()
+
+	tv := vaultik.NewForTesting(mockStorage)
+	ctx := context.Background()
+
+	t.Run("correct hash succeeds", func(t *testing.T) {
+		rc, err := tv.FetchAndDecryptBlob(ctx, correctHash, int64(len(encryptedData)), identity)
+		if err != nil {
+			t.Fatalf("expected success, got error: %v", err)
+		}
+		data, err := io.ReadAll(rc)
+		if err != nil {
+			t.Fatalf("reading stream: %v", err)
+		}
+		if err := rc.Close(); err != nil {
+			t.Fatalf("close (hash verification) failed: %v", err)
+		}
+		if !bytes.Equal(data, plaintext) {
+			t.Fatalf("decrypted data mismatch: got %q, want %q", data, plaintext)
+		}
+	})
+
+	t.Run("wrong hash fails", func(t *testing.T) {
+		// Use a fake hash that doesn't match the actual plaintext
+		fakeHash := strings.Repeat("ab", 32) // 64 hex chars
+		fakePath := "blobs/" + fakeHash[:2] + "/" + fakeHash[2:4] + "/" + fakeHash
+		mockStorage.mu.Lock()
+		mockStorage.data[fakePath] = encryptedData
+		mockStorage.mu.Unlock()
+
+		rc, err := tv.FetchAndDecryptBlob(ctx, fakeHash, int64(len(encryptedData)), identity)
+		if err != nil {
+			t.Fatalf("unexpected error opening stream: %v", err)
+		}
+		// Read all data — hash is verified on Close
+		_, _ = io.ReadAll(rc)
+		err = rc.Close()
+		if err == nil {
+			t.Fatal("expected error for mismatched hash, got nil")
+		}
+		if !strings.Contains(err.Error(), "hash mismatch") {
+			t.Fatalf("expected hash mismatch error, got: %v", err)
+		}
+	})
+}

internal/vaultik/blob_fetch_stub.go

@@ -1,55 +0,0 @@
-package vaultik
-
-import (
-	"context"
-	"fmt"
-	"io"
-
-	"filippo.io/age"
-	"git.eeqj.de/sneak/vaultik/internal/blobgen"
-)
-
-// FetchAndDecryptBlobResult holds the result of fetching and decrypting a blob.
-type FetchAndDecryptBlobResult struct {
-	Data []byte
-}
-
-// FetchAndDecryptBlob downloads a blob, decrypts it, and returns the plaintext data.
-func (v *Vaultik) FetchAndDecryptBlob(ctx context.Context, blobHash string, expectedSize int64, identity age.Identity) (*FetchAndDecryptBlobResult, error) {
-	rc, _, err := v.FetchBlob(ctx, blobHash, expectedSize)
-	if err != nil {
-		return nil, err
-	}
-	defer func() { _ = rc.Close() }()
-
-	reader, err := blobgen.NewReader(rc, identity)
-	if err != nil {
-		return nil, fmt.Errorf("creating blob reader: %w", err)
-	}
-	defer func() { _ = reader.Close() }()
-
-	data, err := io.ReadAll(reader)
-	if err != nil {
-		return nil, fmt.Errorf("reading blob data: %w", err)
-	}
-
-	return &FetchAndDecryptBlobResult{Data: data}, nil
-}
-
-// FetchBlob downloads a blob and returns a reader for the encrypted data.
-func (v *Vaultik) FetchBlob(ctx context.Context, blobHash string, expectedSize int64) (io.ReadCloser, int64, error) {
-	blobPath := fmt.Sprintf("blobs/%s/%s/%s", blobHash[:2], blobHash[2:4], blobHash)
-
-	rc, err := v.Storage.Get(ctx, blobPath)
-	if err != nil {
-		return nil, 0, fmt.Errorf("downloading blob %s: %w", blobHash[:16], err)
-	}
-
-	info, err := v.Storage.Stat(ctx, blobPath)
-	if err != nil {
-		_ = rc.Close()
-		return nil, 0, fmt.Errorf("stat blob %s: %w", blobHash[:16], err)
-	}
-
-	return rc, info.Size, nil
-}

internal/vaultik/restore.go

@@ -558,11 +558,23 @@ func (v *Vaultik) restoreRegularFile(
 
 // downloadBlob downloads and decrypts a blob
 func (v *Vaultik) downloadBlob(ctx context.Context, blobHash string, expectedSize int64, identity age.Identity) ([]byte, error) {
-	result, err := v.FetchAndDecryptBlob(ctx, blobHash, expectedSize, identity)
+	rc, err := v.FetchAndDecryptBlob(ctx, blobHash, expectedSize, identity)
 	if err != nil {
 		return nil, err
 	}
-	return result.Data, nil
+
+	data, err := io.ReadAll(rc)
+	if err != nil {
+		_ = rc.Close()
+		return nil, fmt.Errorf("reading blob data: %w", err)
+	}
+
+	// Close triggers hash verification
+	if err := rc.Close(); err != nil {
+		return nil, err
+	}
+
+	return data, nil
 }
 
 // verifyRestoredFiles verifies that all restored files match their expected chunk hashes

internal/vaultik/snapshot.go

@@ -419,7 +419,7 @@ func (v *Vaultik) listRemoteSnapshotIDs() (map[string]bool, error) {
 	return remoteSnapshots, nil
 }
 
-// reconcileLocalWithRemote removes local snapshots not in remote and returns the surviving local map
+// reconcileLocalWithRemote builds a map of local snapshots keyed by ID for cross-referencing with remote
 func (v *Vaultik) reconcileLocalWithRemote(remoteSnapshots map[string]bool) (map[string]*database.Snapshot, error) {
 	localSnapshots, err := v.Repositories.Snapshots.ListRecent(v.ctx, 10000)
 	if err != nil {
@@ -431,19 +431,6 @@ func (v *Vaultik) reconcileLocalWithRemote(remoteSnapshots map[string]bool) (map
 		localSnapshotMap[s.ID.String()] = s
 	}
 
-	for _, snap := range localSnapshots {
-		snapshotIDStr := snap.ID.String()
-		if !remoteSnapshots[snapshotIDStr] {
-			log.Info("Removing local snapshot not found in remote", "snapshot_id", snap.ID)
-			if err := v.deleteSnapshotFromLocalDB(snapshotIDStr); err != nil {
-				log.Error("Failed to delete local snapshot", "snapshot_id", snap.ID, "error", err)
-			} else {
-				log.Info("Deleted local snapshot not found in remote", "snapshot_id", snap.ID)
-				delete(localSnapshotMap, snapshotIDStr)
-			}
-		}
-	}
-
 	return localSnapshotMap, nil
 }
 
@@ -872,7 +859,7 @@ func (v *Vaultik) syncWithRemote() error {
 		snapshotIDStr := snapshot.ID.String()
 		if !remoteSnapshots[snapshotIDStr] {
 			log.Info("Removing local snapshot not found in remote", "snapshot_id", snapshot.ID)
-			if err := v.Repositories.Snapshots.Delete(v.ctx, snapshotIDStr); err != nil {
+			if err := v.deleteSnapshotFromLocalDB(snapshotIDStr); err != nil {
 				log.Error("Failed to delete local snapshot", "snapshot_id", snapshot.ID, "error", err)
 			} else {
 				removedCount++