tweaks (#1142)

* opt: unused layout

* mod: semantics

* opt: DanmakuMsg type

* opt: avoid cast

* opt: unnecessary_lambdas

* opt: use isEven

* opt: logger

* opt: invalid common page

* tweak

* opt: unify DynController

lib/services/audio_handler.dart

@@ -10,7 +10,7 @@ import 'package:get/get_utils/get_utils.dart';
 
 Future<VideoPlayerServiceHandler> initAudioService() async {
   return AudioService.init(
-    builder: () => VideoPlayerServiceHandler(),
+    builder: VideoPlayerServiceHandler.new,
     config: const AudioServiceConfig(
       androidNotificationChannelId: 'com.example.piliplus.audio',
       androidNotificationChannelName: 'Audio Service PiliPlus',