feat: extension support (#78)

ui/flutter/lib/app/modules/create/controllers/create_controller.dart

@@ -8,8 +8,8 @@ class CreateController extends GetxController
     with GetSingleTickerProviderStateMixin {
   // final files = [].obs;
   final RxList fileInfos = [].obs;
-  final RxList selectedIndexes = [].obs;
   final RxList openedFolders = [].obs;
+  final selectedIndexes = <int>[].obs;
   final isResolving = false.obs;
   final showAdvanced = false.obs;
   late TabController advancedTabController;