implemented dual Nextcloud push registration with separate general and talk apptypes to ensure reliable Talk notification delivery; introduced stacked MessagingStyle notifications for chat threads with support for circular conversation avatars and disk caching

lib/widget/user_avatar.dart

@@ -1,3 +1,4 @@
+import 'dart:async';
 import 'dart:collection';
 import 'dart:convert';
 import 'dart:typed_data';
@@ -8,6 +9,7 @@ import 'package:http/http.dart' as http;
 
 import '../model/account_data.dart';
 import '../model/endpoint_data.dart';
+import '../push/push_avatar.dart';
 
 class UserAvatar extends StatefulWidget {
   final String id;
@@ -86,6 +88,9 @@ void invalidateAvatarCache({String? id, bool? isGroup}) {
     final url = avatarUrl(id: id, isGroup: true);
     _resolvedAvatars.remove(url);
     _pendingAvatars.remove(url);
+    // Keep the push-notification disk cache in sync — it serves the same
+    // room avatar to the FCM background isolate.
+    unawaited(PushAvatarStore.evict(id));
   } else {
     // User avatars include the rendered size in the URL — drop every variant.
     final host = EndpointData().nextcloud().full();
@@ -242,11 +247,7 @@ class _UserAvatarState extends State<UserAvatar> {
       backgroundColor: theme.primaryColor,
       foregroundColor: Colors.white,
       child: ClipOval(
-        child: SizedBox(
-          width: radius * 2,
-          height: radius * 2,
-          child: content,
-        ),
+        child: SizedBox(width: radius * 2, height: radius * 2, child: content),
       ),
     );
   }