refactor: pre seed responses

lib/shared/services/tasks/task_queue.dart

@@ -273,22 +273,7 @@ class TaskQueueNotifier extends StateNotifier<List<OutboundTask>> {
     return id;
   }
 
-  Future<String> enqueueSaveConversation({
-    required String? conversationId,
-    String? idempotencyKey,
-  }) async {
-    final id = _uuid.v4();
-    final task = OutboundTask.saveConversation(
-      id: id,
-      conversationId: conversationId,
-      idempotencyKey: idempotencyKey,
-      enqueuedAt: DateTime.now(),
-    );
-    state = [...state, task];
-    await _save();
-    _process();
-    return id;
-  }
+  // Removed: enqueueSaveConversation — mobile app no longer persists chats to server.
 
   Future<String> enqueueGenerateTitle({
     required String conversationId,