Add custom types, version command, and restore --verify flag

- Add internal/types package with type-safe wrappers for IDs, hashes,
  paths, and credentials (FileID, BlobID, ChunkHash, etc.)
- Implement driver.Valuer and sql.Scanner for UUID-based types
- Add `vaultik version` command showing version, commit, go version
- Add `--verify` flag to restore command that checksums all restored
  files against expected chunk hashes with progress bar
- Remove fetch.go (dead code, functionality in restore)
- Clean up TODO.md, remove completed items
- Update all database and snapshot code to use new custom types

internal/blob/packer.go

@@ -26,6 +26,7 @@ import (
 	"git.eeqj.de/sneak/vaultik/internal/blobgen"
 	"git.eeqj.de/sneak/vaultik/internal/database"
 	"git.eeqj.de/sneak/vaultik/internal/log"
+	"git.eeqj.de/sneak/vaultik/internal/types"
 	"github.com/google/uuid"
 	"github.com/spf13/afero"
 )
@@ -262,19 +263,22 @@ func (p *Packer) startNewBlob() error {
 
 	// Create blob record in database
 	if p.repos != nil {
+		blobIDTyped, err := types.ParseBlobID(blobID)
+		if err != nil {
+			return fmt.Errorf("parsing blob ID: %w", err)
+		}
 		blob := &database.Blob{
-			ID:               blobID,
-			Hash:             "temp-placeholder-" + blobID, // Temporary placeholder until finalized
+			ID:               blobIDTyped,
+			Hash:             types.BlobHash("temp-placeholder-" + blobID), // Temporary placeholder until finalized
 			CreatedTS:        time.Now().UTC(),
 			FinishedTS:       nil,
 			UncompressedSize: 0,
 			CompressedSize:   0,
 			UploadedTS:       nil,
 		}
-		err := p.repos.WithTx(context.Background(), func(ctx context.Context, tx *sql.Tx) error {
+		if err := p.repos.WithTx(context.Background(), func(ctx context.Context, tx *sql.Tx) error {
 			return p.repos.Blobs.Create(ctx, tx, blob)
-		})
-		if err != nil {
+		}); err != nil {
 			return fmt.Errorf("creating blob record: %w", err)
 		}
 	}
@@ -403,11 +407,16 @@ func (p *Packer) finalizeCurrentBlob() error {
 
 	// Insert pending chunks, blob_chunks, and update blob in a single transaction
 	if p.repos != nil {
+		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 {
 			// First insert all pending chunks (required for blob_chunks FK)
 			for _, chunk := range chunksToInsert {
 				dbChunk := &database.Chunk{
-					ChunkHash: chunk.Hash,
+					ChunkHash: types.ChunkHash(chunk.Hash),
 					Size:      chunk.Size,
 				}
 				if err := p.repos.Chunks.Create(ctx, tx, dbChunk); err != nil {
@@ -418,8 +427,8 @@ func (p *Packer) finalizeCurrentBlob() error {
 			// Insert all blob_chunk records in batch
 			for _, chunk := range p.currentBlob.chunks {
 				blobChunk := &database.BlobChunk{
-					BlobID:    p.currentBlob.id,
-					ChunkHash: chunk.Hash,
+					BlobID:    blobIDTyped,
+					ChunkHash: types.ChunkHash(chunk.Hash),
 					Offset:    chunk.Offset,
 					Length:    chunk.Size,
 				}