fix: no attachment broadcast fix

components/chat/message-group.tsx

@@ -190,7 +190,7 @@ export function MessageGroup({
                     {/* An optimistic bubble for a captionless attachment has
                       nothing to draw until the server answers — say so rather
                       than render an empty box. */}
-                    {m.pending && !m.body && m.attachments.length === 0 && (
+                    {m.pending && !m.body && !m.attachments?.length && (
                       <span className="italic opacity-80">
                         Sending attachment…
                       </span>

components/notifications/broadcast-modal.tsx

@@ -60,7 +60,9 @@ export function BroadcastModal() {
     }
   }, [item, dismissing]);
 
-  if (!item) return null;
+  // Guard on the shape, not just presence: a malformed payload must not put
+  // an empty modal over every page in the app.
+  if (!item?.id || !item.title) return null;
 
   return (
     <ResponsiveDialog