feat(playlist): 增加歌单播放次数功能

- 在前端 PlaylistDetail.vue 中添加播放全部歌曲时增加播放次数的逻辑- 在后端 PlaylistServiceImpl 中实现 playPlaylist 方法，增加歌单播放次数
- 优化了播放全部歌曲的功能，包括处理播放次数增加失败的情况

music-houduan/src/main/java/com/test/musichouduan/service/impl/PlaylistServiceImpl.java

@@ -519,13 +519,17 @@ public class PlaylistServiceImpl implements PlaylistService {
     @Override
     @Transactional
     public PlaylistDTO playPlaylist(Long id) {
+        System.out.println("接收到播放歌单请求，歌单ID: " + id);
         // 获取歌单
         Playlist playlist = playlistRepository.findById(id)
                 .orElseThrow(() -> new BusinessException("歌单不存在"));
 
         // 增加播放次数
-        playlist.setPlayCount(playlist.getPlayCount() + 1);
+        long currentPlayCount = playlist.getPlayCount() == null ? 0 : playlist.getPlayCount();
+        System.out.println("当前播放次数: " + currentPlayCount);
+        playlist.setPlayCount(currentPlayCount + 1);
         playlistRepository.save(playlist);
+        System.out.println("播放次数已增加，更新后为: " + playlist.getPlayCount());
 
         return convertToDTO(playlist);
     }