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/database/cascade_debug_test.go

@@ -5,6 +5,8 @@ import (
 	"fmt"
 	"testing"
 	"time"
+
+	"git.eeqj.de/sneak/vaultik/internal/types"
 )
 
 // TestCascadeDeleteDebug tests cascade delete with debug output
@@ -42,7 +44,7 @@ func TestCascadeDeleteDebug(t *testing.T) {
 	// Create chunks and file-chunk mappings
 	for i := 0; i < 3; i++ {
 		chunk := &Chunk{
-			ChunkHash: fmt.Sprintf("cascade-chunk-%d", i),
+			ChunkHash: types.ChunkHash(fmt.Sprintf("cascade-chunk-%d", i)),
 			Size:      1024,
 		}
 		err = repos.Chunks.Create(ctx, nil, chunk)