refactor(music): 优化歌单相关功能

- 初始化歌单属性默认值，避免空值- 调整歌单信息布局，优化界面显示
-修复歌单播放次数空值问题，提升数据准确性

music-houduan/src/main/java/com/test/musichouduan/entity/Playlist.java

@@ -57,25 +57,25 @@ public class Playlist {
      * 是否官方歌单：0-否，1-是
      */
     @Column
-    private Integer isOfficial;
+    private Integer isOfficial = 0;
 
     /**
      * 收藏数
      */
     @Column
-    private Integer collectCount;
+    private Integer collectCount = 0;
 
     /**
      * 评论数
      */
     @Column
-    private Integer commentCount;
+    private Integer commentCount = 0;
 
     /**
      * 播放次数
      */
     @Column
-    private Long playCount;
+    private Long playCount = 0L;
 
     /**
      * 歌单中的音乐

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

@@ -546,6 +546,9 @@ public class PlaylistServiceImpl implements PlaylistService {
         PlaylistDTO playlistDTO = new PlaylistDTO();
         BeanUtils.copyProperties(playlist, playlistDTO);
         playlistDTO.setHotScore(playlist.getHotScore());
+        if (playlist.getPlayCount() == null) {
+            playlistDTO.setPlayCount(0L);
+        }
 
         // 设置创建者信息
         if (playlist.getCreator() != null) {

music-qianduan/src/views/Playlist.vue

@@ -503,7 +503,8 @@ onMounted(() => {
   transition: opacity 0.3s;
   display: flex;
   flex-direction: column;
-  justify-content: space-between;
+  justify-content: flex-start;
+  gap: 5px;
   padding: 15px;
 }