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/snapshots_test.go

@@ -6,6 +6,8 @@ import (
 	"math"
 	"testing"
 	"time"
+
+	"git.eeqj.de/sneak/vaultik/internal/types"
 )
 
 const (
@@ -46,7 +48,7 @@ func TestSnapshotRepository(t *testing.T) {
 	}
 
 	// Test GetByID
-	retrieved, err := repo.GetByID(ctx, snapshot.ID)
+	retrieved, err := repo.GetByID(ctx, snapshot.ID.String())
 	if err != nil {
 		t.Fatalf("failed to get snapshot: %v", err)
 	}
@@ -64,12 +66,12 @@ func TestSnapshotRepository(t *testing.T) {
 	}
 
 	// Test UpdateCounts
-	err = repo.UpdateCounts(ctx, nil, snapshot.ID, 200, 1000, 20, twoHundredMebibytes, sixtyMebibytes)
+	err = repo.UpdateCounts(ctx, nil, snapshot.ID.String(), 200, 1000, 20, twoHundredMebibytes, sixtyMebibytes)
 	if err != nil {
 		t.Fatalf("failed to update counts: %v", err)
 	}
 
-	retrieved, err = repo.GetByID(ctx, snapshot.ID)
+	retrieved, err = repo.GetByID(ctx, snapshot.ID.String())
 	if err != nil {
 		t.Fatalf("failed to get updated snapshot: %v", err)
 	}
@@ -97,7 +99,7 @@ func TestSnapshotRepository(t *testing.T) {
 	// Add more snapshots
 	for i := 2; i <= 5; i++ {
 		s := &Snapshot{
-			ID:             fmt.Sprintf("2024-01-0%dT12:00:00Z", i),
+			ID:             types.SnapshotID(fmt.Sprintf("2024-01-0%dT12:00:00Z", i)),
 			Hostname:       "test-host",
 			VaultikVersion: "1.0.0",
 			StartedAt:      time.Now().Add(time.Duration(i) * time.Hour).Truncate(time.Second),