Core Freeze：核心链路功能已经完成设计，后续进入beta功能开发模式，接下来会在UI部分微调后，进入首个Release版本（1.1.0-Release）

lib/services/audio_service.dart

@@ -779,7 +779,6 @@ class AudioService extends ChangeNotifier {
     debugPrint('💾 [AudioService] playback state saved');
   }
 
-  /// 恢复播放状态
   /// 恢复播放状态
   Future<bool> restorePlaybackState() async {
     final state = await _db.getPlaybackState();
@@ -803,7 +802,9 @@ class AudioService extends ChangeNotifier {
 
       _queue = queue;
       _currentIndex = state['current_index'] as int;
-      if (_currentIndex >= _queue.length) _currentIndex = 0;
+      if (_currentIndex < 0 || _currentIndex >= _queue.length) {
+        _currentIndex = 0;
+      }
 
       final modeStr = state['play_mode'] as String? ?? 'sequential';
       _playMode = modeStr == 'sequential'
@@ -813,6 +814,20 @@ class AudioService extends ChangeNotifier {
               : PlayMode.shuffle;
       _currentPlaylistId = state['current_playlist_id'] as String?;
 
+      // ⭐⭐⭐ 关键修复：重建 _shuffledIndices 和 _shuffledIndex ⭐⭐⭐
+      if (_playMode == PlayMode.shuffle) {
+        _shuffledIndices = List.generate(_queue.length, (i) => i);
+        _shuffledIndices.shuffle();
+        _shuffledIndex = _shuffledIndices.indexOf(_currentIndex);
+        if (_shuffledIndex == -1) {
+          _shuffledIndex = 0;
+          _currentIndex = _shuffledIndices[0];
+        }
+      } else {
+        _shuffledIndices = List.generate(_queue.length, (i) => i);
+        _shuffledIndex = _currentIndex;
+      }
+
       // 保存待恢复的进度
       final savedPos = state['position_ms'] as int? ?? 0;
       _pendingSeekPosition = Duration(milliseconds: savedPos);
@@ -821,10 +836,11 @@ class AudioService extends ChangeNotifier {
       _currentSong = song;
       _onSongChanged?.call(song);
 
-      debugPrint(
-          '♻️ [AudioService] playback state restored: ${song.title} - ${song.artist}');
+      debugPrint('♻️ [AudioService] playback state restored: '
+          'queue=${_queue.length}, index=$_currentIndex, '
+          'song=${song.title}, mode=$_playMode');
 
-      // ⭐ 关键：加载音频但不自动播放
+      // ⭐ 加载音频但不自动播放
       await _loadRestoredPlayback();
 
       return true;