Close WebSocket when InitWidget state is disposed

lib/ui/widgets/init_widget.dart

@@ -32,6 +32,12 @@ class _InitializeWidgetState extends SafeState<InitializeWidget> {
     super.listen<WSClosedEvent>((e) => _tryConnect());
   }
 
+  @override
+  void dispose() {
+    super.dispose();
+    WebSocketHelper.close();
+  }
+
   /// Try to connect to server
   void _tryConnect() async {
     try {