Harden backup and restore operations

cmd/urbmd/main.go

@@ -87,5 +87,8 @@ func main() {
 	shutdownCtx, shutdownCancel := context.WithTimeout(context.Background(), 15*time.Second)
 	defer shutdownCancel()
 	_ = server.Shutdown(shutdownCtx)
+	if err := svc.Wait(shutdownCtx); err != nil {
+		log.Warn("queue cleanup did not finish before shutdown timeout", "error", err)
+	}
 	log.Info("urbm daemon stopped")
 }