暂时把bug先处理掉了，准备尝试实现最小播放目标

lib/services/audio_service.dart

@@ -1,7 +1,19 @@
 import 'package:flutter/material.dart';
-import '../models/song_model.dart';
 
-// 这是一个 ChangeNotifier，以后用来刷新底部的迷你播放条
+class Song {
+  final String id;
+  final String title;
+  final String artist;
+  final String? url;
+
+  Song({
+    required this.id,
+    required this.title,
+    required this.artist,
+    this.url,
+  });
+}
+
 class AudioService extends ChangeNotifier {
   Song? _currentSong;
   bool _isPlaying = false;
@@ -9,16 +21,20 @@ class AudioService extends ChangeNotifier {
   Song? get currentSong => _currentSong;
   bool get isPlaying => _isPlaying;
 
-  // 占位方法：以后这里会调用 media_kit
   void playSong(Song song) {
     _currentSong = song;
     _isPlaying = true;
-    notifyListeners(); // 刷新 UI
-    print('🎵 准备播放: ${song.title} - ${song.artist}');
+    notifyListeners();
   }
 
   void togglePlay() {
     _isPlaying = !_isPlaying;
     notifyListeners();
   }
+
+  void stopPlay() {
+    _currentSong = null;
+    _isPlaying = false;
+    notifyListeners();
+  }
 }