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/vaultik/helpers.go

@@ -5,13 +5,15 @@ import (
 	"strconv"
 	"strings"
 	"time"
+
+	"git.eeqj.de/sneak/vaultik/internal/types"
 )
 
 // SnapshotInfo contains information about a snapshot
 type SnapshotInfo struct {
-	ID             string    `json:"id"`
-	Timestamp      time.Time `json:"timestamp"`
-	CompressedSize int64     `json:"compressed_size"`
+	ID             types.SnapshotID `json:"id"`
+	Timestamp      time.Time        `json:"timestamp"`
+	CompressedSize int64            `json:"compressed_size"`
 }
 
 // formatNumber formats a number with commas
@@ -60,27 +62,18 @@ func formatBytes(bytes int64) string {
 }
 
 // parseSnapshotTimestamp extracts the timestamp from a snapshot ID
+// Format: hostname_snapshotname_2026-01-12T14:41:15Z
 func parseSnapshotTimestamp(snapshotID string) (time.Time, error) {
-	// Format: hostname-YYYYMMDD-HHMMSSZ
-	parts := strings.Split(snapshotID, "-")
-	if len(parts) < 3 {
-		return time.Time{}, fmt.Errorf("invalid snapshot ID format")
+	parts := strings.Split(snapshotID, "_")
+	if len(parts) < 2 {
+		return time.Time{}, fmt.Errorf("invalid snapshot ID format: expected hostname_snapshotname_timestamp")
 	}
 
-	dateStr := parts[len(parts)-2]
-	timeStr := parts[len(parts)-1]
-
-	if len(dateStr) != 8 || len(timeStr) != 7 || !strings.HasSuffix(timeStr, "Z") {
-		return time.Time{}, fmt.Errorf("invalid timestamp format")
-	}
-
-	// Remove Z suffix
-	timeStr = timeStr[:6]
-
-	// Parse the timestamp
-	timestamp, err := time.Parse("20060102150405", dateStr+timeStr)
+	// Last part is the RFC3339 timestamp
+	timestampStr := parts[len(parts)-1]
+	timestamp, err := time.Parse(time.RFC3339, timestampStr)
 	if err != nil {
-		return time.Time{}, fmt.Errorf("failed to parse timestamp: %w", err)
+		return time.Time{}, fmt.Errorf("invalid timestamp: %w", err)
 	}
 
 	return timestamp.UTC(), nil