setScreen指令，等待实际处理完成之后再返回结果

lib/data/repositories/message/screen_handler.dart

@@ -9,28 +9,28 @@ class ScreenHandler extends MessageHandler {
     }
 
     int type = params['type'];
-    _setOrientation(type);
+    await _setOrientation(type);
 
     return true;
   }
 
-  void _setOrientation(int screenType) {
+  Future<void> _setOrientation(int screenType) async {
     if (screenType == 2) {
       // 横屏模式
-      SystemChrome.setPreferredOrientations([
+      await SystemChrome.setPreferredOrientations([
         DeviceOrientation.landscapeLeft,
         DeviceOrientation.landscapeRight,
       ]);
       // 隐藏状态栏
-      SystemChrome.setEnabledSystemUIMode(SystemUiMode.immersive);
+      await SystemChrome.setEnabledSystemUIMode(SystemUiMode.immersive);
     } else {
       // 竖屏模式（默认）
-      SystemChrome.setPreferredOrientations([
+      await SystemChrome.setPreferredOrientations([
         DeviceOrientation.portraitUp,
         DeviceOrientation.portraitDown,
       ]);
       // 显示状态栏
-      SystemChrome.setEnabledSystemUIMode(SystemUiMode.edgeToEdge);
+      await SystemChrome.setEnabledSystemUIMode(SystemUiMode.edgeToEdge);
     }
   }
 }