fix(web): handle delete failure in confirm dialog (no unhandled rejection)

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

web/src/objects/delete-object-dialog.tsx

@@ -20,9 +20,18 @@ export function DeleteObjectDialog({ id }: { id: string }) {
   const navigate = useNavigate();
   const del = useDeleteObject();
   const [open, setOpen] = useState(false);
+  const [error, setError] = useState(false);
 
   const onConfirm = async () => {
+    setError(false);
+    try {
       await del.mutateAsync(id);
+    } catch {
+      // Keep the dialog open so the user can retry or cancel; never let the
+      // rejected mutation escape as an unhandled promise rejection.
+      setError(true);
+      return;
+    }
     navigate("/objects");
   };
 
@@ -39,6 +48,11 @@ export function DeleteObjectDialog({ id }: { id: string }) {
       <AlertDialogContent>
         <AlertDialogTitle>{t("actions.delete")}</AlertDialogTitle>
         <AlertDialogDescription>{t("actions.confirmDelete")}</AlertDialogDescription>
+        {error && (
+          <p role="alert" className="text-sm text-red-600">
+            {t("form.rejected")}
+          </p>
+        )}
         <AlertDialogFooter>
           <AlertDialogCancel>{t("form.cancel")}</AlertDialogCancel>
           <AlertDialogAction onClick={onConfirm}>