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/cli/entry_test.go

@@ -18,7 +18,7 @@ func TestCLIEntry(t *testing.T) {
 	}
 
 	// Verify all subcommands are registered
-	expectedCommands := []string{"snapshot", "store", "restore", "prune", "verify", "fetch"}
+	expectedCommands := []string{"snapshot", "store", "restore", "prune", "verify", "info", "version"}
 	for _, expected := range expectedCommands {
 		found := false
 		for _, cmd := range cmd.Commands() {