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_test.go

@@ -12,6 +12,7 @@ import (
 	"filippo.io/age"
 	"git.eeqj.de/sneak/vaultik/internal/database"
 	"git.eeqj.de/sneak/vaultik/internal/log"
+	"git.eeqj.de/sneak/vaultik/internal/types"
 	"github.com/klauspost/compress/zstd"
 	"github.com/spf13/afero"
 )
@@ -60,7 +61,7 @@ func TestPacker(t *testing.T) {
 
 		// Create chunk in database first
 		dbChunk := &database.Chunk{
-			ChunkHash: hashStr,
+			ChunkHash: types.ChunkHash(hashStr),
 			Size:      int64(len(data)),
 		}
 		err = repos.WithTx(context.Background(), func(ctx context.Context, tx *sql.Tx) error {
@@ -152,7 +153,7 @@ func TestPacker(t *testing.T) {
 
 			// Create chunk in database first
 			dbChunk := &database.Chunk{
-				ChunkHash: hashStr,
+				ChunkHash: types.ChunkHash(hashStr),
 				Size:      int64(len(data)),
 			}
 			err = repos.WithTx(context.Background(), func(ctx context.Context, tx *sql.Tx) error {
@@ -235,7 +236,7 @@ func TestPacker(t *testing.T) {
 
 			// Create chunk in database first
 			dbChunk := &database.Chunk{
-				ChunkHash: hashStr,
+				ChunkHash: types.ChunkHash(hashStr),
 				Size:      int64(len(data)),
 			}
 			err = repos.WithTx(context.Background(), func(ctx context.Context, tx *sql.Tx) error {
@@ -322,7 +323,7 @@ func TestPacker(t *testing.T) {
 
 		// Create chunk in database first
 		dbChunk := &database.Chunk{
-			ChunkHash: hashStr,
+			ChunkHash: types.ChunkHash(hashStr),
 			Size:      int64(len(data)),
 		}
 		err = repos.WithTx(context.Background(), func(ctx context.Context, tx *sql.Tx) error {