全部包名与名称确定，后台播放能力已完整，准备进入媒体信息推送部分

lib/services/audio_service.dart

@@ -48,6 +48,9 @@ class AudioService extends ChangeNotifier {
   bool _listening = false;
   final List<StreamSubscription> _subscriptions = [];
 
+  // ⭐ 防重入标志
+  bool _handlingCompletion = false;
+
   // ---- Getter（高频字段不走 ChangeNotifier） ----
   Song? get currentSong => _currentSong;
   bool get isPlaying => _isPlaying;
@@ -240,12 +243,11 @@ class AudioService extends ChangeNotifier {
       player.stream.playing.listen((playing) {
         if (_isPlaying != playing) {
           _isPlaying = playing;
-          notifyListeners(); // 只有播放状态变化才刷新
+          notifyListeners();
         }
       }),
     );
 
-    // ⭐ 进度更新：只更新 ValueNotifier，不触发全局重建
     _subscriptions.add(
       player.stream.position.listen((position) {
         positionNotifier.value = position;
@@ -264,6 +266,7 @@ class AudioService extends ChangeNotifier {
       }),
     );
 
+    // ⭐ 唯一监听 completed 的地方
     _subscriptions.add(
       player.stream.completed.listen((_) {
         _onPlaybackCompleted();
@@ -279,15 +282,23 @@ class AudioService extends ChangeNotifier {
     _subscriptions.clear();
   }
 
+  // ⭐ 防重入
   void _onPlaybackCompleted() {
-    if (_queue.isEmpty) return;
-
-    if (_playMode == PlayMode.repeatOne) {
-      _playCurrent();
+    if (_handlingCompletion) {
+      debugPrint('⚠️ [service] completed ignored: already handling');
       return;
     }
-
-    next();
+    _handlingCompletion = true;
+    try {
+      if (_queue.isEmpty) return;
+      if (_playMode == PlayMode.repeatOne) {
+        _playCurrent();
+        return;
+      }
+      next();
+    } finally {
+      _handlingCompletion = false;
+    }
   }
 
   @override