wait for metadata to come in on notif's rooms before sending them

lib/controllers/notification.dart

@@ -68,6 +68,8 @@ class NotificationController
           );
         }
       });
+
+      ref.onDispose(() => notificationChannel.setMethodCallHandler(null));
     }
 
     return notifications;

lib/controllers/unified_push.dart

@@ -1,3 +1,4 @@
+import "dart:async";
 import "dart:convert";
 import "dart:io";
 
@@ -78,10 +79,30 @@ class UnifiedPushController extends AsyncNotifier<bool> {
           return;
         }
 
-        final room = ref.read(
-          RoomsController.provider.select((rooms) => rooms[event.roomId]),
+        final provider = RoomsController.provider.select(
+          (rooms) => rooms[event.roomId],
         );
 
+        if (ref.read(provider)?.metadata != null) return;
+
+        final completer = Completer<void>();
+
+        final subscription = ref.listen(provider, (previous, next) {
+          if (next?.metadata != null && !completer.isCompleted) {
+            completer.complete();
+          }
+        });
+
+        try {
+          await completer.future.timeout(const .new(seconds: 10));
+        } on TimeoutException {
+          // metadata didn't show up in time
+        } finally {
+          subscription.close();
+        }
+
+        final room = ref.read(provider);
+
         final avatar = room?.metadata?.avatar;
         final icon = avatar == null
             ? null