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/repository_edge_cases_test.go

@@ -6,6 +6,8 @@ import (
 	"strings"
 	"testing"
 	"time"
+
+	"git.eeqj.de/sneak/vaultik/internal/types"
 )
 
 // TestFileRepositoryEdgeCases tests edge cases for file repository
@@ -38,7 +40,7 @@ func TestFileRepositoryEdgeCases(t *testing.T) {
 		{
 			name: "very long path",
 			file: &File{
-				Path:  "/" + strings.Repeat("a", 4096),
+				Path:  types.FilePath("/" + strings.Repeat("a", 4096)),
 				MTime: time.Now(),
 				CTime: time.Now(),
 				Size:  1024,
@@ -94,7 +96,7 @@ func TestFileRepositoryEdgeCases(t *testing.T) {
 		t.Run(tt.name, func(t *testing.T) {
 			// Add a unique suffix to paths to avoid UNIQUE constraint violations
 			if tt.file.Path != "" {
-				tt.file.Path = fmt.Sprintf("%s_%d_%d", tt.file.Path, i, time.Now().UnixNano())
+				tt.file.Path = types.FilePath(fmt.Sprintf("%s_%d_%d", tt.file.Path, i, time.Now().UnixNano()))
 			}
 
 			err := repo.Create(ctx, nil, tt.file)
@@ -169,7 +171,7 @@ func TestDuplicateHandling(t *testing.T) {
 	// Test duplicate chunk hashes
 	t.Run("duplicate chunk hashes", func(t *testing.T) {
 		chunk := &Chunk{
-			ChunkHash: "duplicate-chunk",
+			ChunkHash: types.ChunkHash("duplicate-chunk"),
 			Size:      1024,
 		}
 
@@ -202,7 +204,7 @@ func TestDuplicateHandling(t *testing.T) {
 		}
 
 		chunk := &Chunk{
-			ChunkHash: "test-chunk-dup",
+			ChunkHash: types.ChunkHash("test-chunk-dup"),
 			Size:      1024,
 		}
 		err = repos.Chunks.Create(ctx, nil, chunk)
@@ -279,7 +281,7 @@ func TestNullHandling(t *testing.T) {
 			t.Fatal(err)
 		}
 
-		retrieved, err := repos.Snapshots.GetByID(ctx, snapshot.ID)
+		retrieved, err := repos.Snapshots.GetByID(ctx, snapshot.ID.String())
 		if err != nil {
 			t.Fatal(err)
 		}
@@ -292,8 +294,8 @@ func TestNullHandling(t *testing.T) {
 	// Test blob with NULL uploaded_ts
 	t.Run("blob not uploaded", func(t *testing.T) {
 		blob := &Blob{
-			ID:         "not-uploaded",
-			Hash:       "test-hash",
+			ID:         types.NewBlobID(),
+			Hash:       types.BlobHash("test-hash"),
 			CreatedTS:  time.Now(),
 			UploadedTS: nil, // Not uploaded yet
 		}
@@ -303,7 +305,7 @@ func TestNullHandling(t *testing.T) {
 			t.Fatal(err)
 		}
 
-		retrieved, err := repos.Blobs.GetByID(ctx, blob.ID)
+		retrieved, err := repos.Blobs.GetByID(ctx, blob.ID.String())
 		if err != nil {
 			t.Fatal(err)
 		}
@@ -339,13 +341,13 @@ func TestLargeDatasets(t *testing.T) {
 
 	// Create many files
 	const fileCount = 1000
-	fileIDs := make([]string, fileCount)
+	fileIDs := make([]types.FileID, fileCount)
 
 	t.Run("create many files", func(t *testing.T) {
 		start := time.Now()
 		for i := 0; i < fileCount; i++ {
 			file := &File{
-				Path:  fmt.Sprintf("/large/file%05d.txt", i),
+				Path:  types.FilePath(fmt.Sprintf("/large/file%05d.txt", i)),
 				MTime: time.Now(),
 				CTime: time.Now(),
 				Size:  int64(i * 1024),
@@ -361,7 +363,7 @@ func TestLargeDatasets(t *testing.T) {
 
 			// Add half to snapshot
 			if i%2 == 0 {
-				err = repos.Snapshots.AddFileByID(ctx, nil, snapshot.ID, file.ID)
+				err = repos.Snapshots.AddFileByID(ctx, nil, snapshot.ID.String(), file.ID)
 				if err != nil {
 					t.Fatal(err)
 				}
@@ -413,7 +415,7 @@ func TestErrorPropagation(t *testing.T) {
 
 	// Test GetByID with non-existent ID
 	t.Run("GetByID non-existent", func(t *testing.T) {
-		file, err := repos.Files.GetByID(ctx, "non-existent-uuid")
+		file, err := repos.Files.GetByID(ctx, types.NewFileID())
 		if err != nil {
 			t.Errorf("GetByID should not return error for non-existent ID, got: %v", err)
 		}
@@ -436,9 +438,9 @@ func TestErrorPropagation(t *testing.T) {
 	// Test invalid foreign key reference
 	t.Run("invalid foreign key", func(t *testing.T) {
 		fc := &FileChunk{
-			FileID:    "non-existent-file-id",
+			FileID:    types.NewFileID(),
 			Idx:       0,
-			ChunkHash: "some-chunk",
+			ChunkHash: types.ChunkHash("some-chunk"),
 		}
 		err := repos.FileChunks.Create(ctx, nil, fc)
 		if err == nil {
@@ -470,7 +472,7 @@ func TestQueryInjection(t *testing.T) {
 		t.Run("injection attempt", func(t *testing.T) {
 			// Try injection in file path
 			file := &File{
-				Path:  injection,
+				Path:  types.FilePath(injection),
 				MTime: time.Now(),
 				CTime: time.Now(),
 				Size:  1024,