music: 新建 music app，替换 piano-sheet

听歌 + 练琴曲目管理：
- 数据：piece (title/artist/category/lyrics/play_count/notes) + attachments (audio/video/pdf/image; image 带 role=chord/numbered/staff)
- 后端 axum + sqlite，附件流式落 PVC，ServeFile 支持 Range（视频拖动）
- 前端 guitar 风格 player：左 sidebar + tabs(歌词/吉他谱/简谱/五线谱/PDF/视频)，LRC 同步、快捷键、笔记自动保存
- ns cube-music + music.famzheng.me + bodylimit 5GiB
- scripts/import_guitar.py 用于把 oci /data/guitar/ 旧曲库导入

apps/music/frontend/package.json

@@ -0,0 +1,19 @@
+{
+  "name": "music",
+  "private": true,
+  "version": "1.0.0",
+  "scripts": {
+    "dev": "vite",
+    "build": "vite build",
+    "preview": "vite preview"
+  },
+  "dependencies": {
+    "pinia": "^2.1.7",
+    "vue": "^3.4.21",
+    "vue-router": "^4.3.0"
+  },
+  "devDependencies": {
+    "@vitejs/plugin-vue": "^5.0.4",
+    "vite": "^5.4.0"
+  }
+}