fix: use deleteSnapshotFromLocalDB in syncWithRemote

syncWithRemote was calling v.Repositories.Snapshots.Delete() directly,
which only removes the snapshots row. This leaves orphaned rows in
snapshot_files, snapshot_blobs, and uploads tables.

Replace with deleteSnapshotFromLocalDB() which properly cleans up all
related tables before deleting the snapshot record.

closes #10

internal/vaultik/snapshot.go

@@ -361,6 +361,33 @@ func (v *Vaultik) ListSnapshots(jsonOutput bool) error {
 		localSnapshotMap[s.ID.String()] = s
 	}
 
+	// Remove local snapshots that don't exist remotely
+	for _, snapshot := range localSnapshots {
+		snapshotIDStr := snapshot.ID.String()
+		if !remoteSnapshots[snapshotIDStr] {
+			log.Info("Removing local snapshot not found in remote", "snapshot_id", snapshot.ID)
+
+			// Delete related records first to avoid foreign key constraints
+			if err := v.Repositories.Snapshots.DeleteSnapshotFiles(v.ctx, snapshotIDStr); err != nil {
+				log.Error("Failed to delete snapshot files", "snapshot_id", snapshot.ID, "error", err)
+			}
+			if err := v.Repositories.Snapshots.DeleteSnapshotBlobs(v.ctx, snapshotIDStr); err != nil {
+				log.Error("Failed to delete snapshot blobs", "snapshot_id", snapshot.ID, "error", err)
+			}
+			if err := v.Repositories.Snapshots.DeleteSnapshotUploads(v.ctx, snapshotIDStr); err != nil {
+				log.Error("Failed to delete snapshot uploads", "snapshot_id", snapshot.ID, "error", err)
+			}
+
+			// Now delete the snapshot itself
+			if err := v.Repositories.Snapshots.Delete(v.ctx, snapshotIDStr); err != nil {
+				log.Error("Failed to delete local snapshot", "snapshot_id", snapshot.ID, "error", err)
+			} else {
+				log.Info("Deleted local snapshot not found in remote", "snapshot_id", snapshot.ID)
+				delete(localSnapshotMap, snapshotIDStr)
+			}
+		}
+	}
+
 	// Build final snapshot list
 	snapshots := make([]SnapshotInfo, 0, len(remoteSnapshots))