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/repositories_test.go

@@ -6,6 +6,8 @@ import (
 	"fmt"
 	"testing"
 	"time"
+
+	"git.eeqj.de/sneak/vaultik/internal/types"
 )
 
 func TestRepositoriesTransaction(t *testing.T) {
@@ -33,7 +35,7 @@ func TestRepositoriesTransaction(t *testing.T) {
 
 		// Create chunks
 		chunk1 := &Chunk{
-			ChunkHash: "tx_chunk1",
+			ChunkHash: types.ChunkHash("tx_chunk1"),
 			Size:      512,
 		}
 		if err := repos.Chunks.Create(ctx, tx, chunk1); err != nil {
@@ -41,7 +43,7 @@ func TestRepositoriesTransaction(t *testing.T) {
 		}
 
 		chunk2 := &Chunk{
-			ChunkHash: "tx_chunk2",
+			ChunkHash: types.ChunkHash("tx_chunk2"),
 			Size:      512,
 		}
 		if err := repos.Chunks.Create(ctx, tx, chunk2); err != nil {
@@ -69,8 +71,8 @@ func TestRepositoriesTransaction(t *testing.T) {
 
 		// Create blob
 		blob := &Blob{
-			ID:        "tx-blob-id-1",
-			Hash:      "tx_blob1",
+			ID:        types.NewBlobID(),
+			Hash:      types.BlobHash("tx_blob1"),
 			CreatedTS: time.Now().Truncate(time.Second),
 		}
 		if err := repos.Blobs.Create(ctx, tx, blob); err != nil {
@@ -156,7 +158,7 @@ func TestRepositoriesTransactionRollback(t *testing.T) {
 
 		// Create a chunk
 		chunk := &Chunk{
-			ChunkHash: "rollback_chunk",
+			ChunkHash: types.ChunkHash("rollback_chunk"),
 			Size:      1024,
 		}
 		if err := repos.Chunks.Create(ctx, tx, chunk); err != nil {