feat: 云盘/下载音乐分离/粘性头部/播放状态同步/歌手关注

新增:
- 音乐云盘页面(列表/详情弹窗/删除/存储空间, NOS multipart上传+LBS区域查询+进度事件)
- 下载音乐页面(独立于本地音乐, 只显示应用下载的歌曲)
- PageHeader粘性头部组件(IntersectionObserver控制显隐, 渐变模糊背景)
- useLocalMusic composable(LocalSong类型/formatFileSize/localSongToSong/fetchMissingCovers)
- 云盘上传完整流程(cloud_upload命令: check->token->LBS->NOS分块上传->info->publish)
- 云盘API(user_cloud/user_cloud_detail/user_cloud_del)
- 歌手关注/取关(artist_sub/artist_sublist命令, ArtistDetail关注按钮+artistSublist查询状态)
- 本地音乐多文件夹扫描(scan_local_folders命令, settings.localMusicPaths, 模态框管理)
- 侧边栏下载音乐和云盘导航项, 路由新增downloaded-music和cloud-music
- md5 crate依赖

改进:
- 路由全部改为懒加载
- keep-alive缓存管理重写(30s TTL+导航栈保护+FavoriteSongs常驻+10s定时清理)
- 播放器状态同步改为轮询isAudioPlaying(替代audio-started事件), 超时后watchForLatePlayback继续监听
- audio.rs新增is_playing原子状态+is_audio_playing命令
- 同步命令改async+spawn_blocking(list_local_songs/delete_local_song/check_local_song/get_default_download_path)
- scan_dir_for_songs抽取为公共函数, 新增downloaded_only参数
- RoamDrawer tab状态从组件本地ref移至store(roamTab替换roamInitialTab)
- App.vue onMounted改为非阻塞
- 多页面添加骨架屏加载态和加载失败重试
- 多页面使用PageHeader替代手动返回按钮
- PlaylistDetail/ArtistDetail添加简介弹窗(溢出时显示查看完整介绍)
- Home推荐/排行榜拆分为独立fetch函数支持分别重试
- Toast去重(3s窗口)+数量限制(最多3条)
- LocalMusic移除删除功能改文件夹模态框, ArtistDetail头像改圆形简介内嵌
- README重写

修复:
- 播放超时后后端实际开始播放但UI显示暂停(watchForLatePlayback+tick定期同步isAudioPlaying)
- FM播放缺少playSeq竞态保护
- scrobble离线时仍发送(添加navigator.onLine检查)
- RoamDrawer已打开时点击评论按钮无法切换(roamTab移至store)
- 关闭RoamDrawer后再打开永远显示评论(closeRoamDrawer重置roamTab)
- 歌手详情页关注状态离开后丢失(artist_detail不返回followed, 改用artistSublist查询)
- audio-ended事件在切歌时误触发(新增_switchingSong标志拦截)
- 路由beforeEach中localStorage key从user改为user_profile
- toggle播放前先同步后端状态

src/stores/settings.ts

@@ -66,6 +66,7 @@ export const defaultShortcuts: Record<string, ShortcutBinding> = {
 interface SettingsData {
   audioQuality: AudioQuality;
   downloadPath: string;
+  localMusicPaths: string[];
   theme: ThemeColor;
   appearance: Appearance;
   closeAction: CloseAction;
@@ -87,6 +88,7 @@ function loadSettings(): SettingsData {
         return {
           audioQuality: parsed.audioQuality || 'standard',
           downloadPath: parsed.downloadPath || '',
+          localMusicPaths: parsed.localMusicPaths || [],
           theme: validThemes.includes(parsed.theme.slice(6)) ? parsed.theme.slice(6) : 'blue',
           appearance: 'light',
           closeAction: parsed.closeAction || 'ask',
@@ -98,6 +100,7 @@ function loadSettings(): SettingsData {
       return {
         audioQuality: parsed.audioQuality || 'standard',
         downloadPath: parsed.downloadPath || '',
+        localMusicPaths: parsed.localMusicPaths || [],
         theme: validThemes.includes(theme) ? theme : 'blue',
         appearance,
         closeAction: parsed.closeAction || 'ask',
@@ -110,6 +113,7 @@ function loadSettings(): SettingsData {
   return {
     audioQuality: 'standard',
     downloadPath: '',
+    localMusicPaths: [],
     theme: 'blue',
     appearance: 'dark',
     closeAction: 'ask',
@@ -124,6 +128,7 @@ export const useSettingsStore = defineStore('settings', () => {
 
   const audioQuality = ref<AudioQuality>(saved.audioQuality);
   const downloadPath = ref<string>(saved.downloadPath);
+  const localMusicPaths = ref<string[]>(saved.localMusicPaths);
   const theme = ref<ThemeColor>(saved.theme);
   const appearance = ref<Appearance>(saved.appearance);
   const closeAction = ref<CloseAction>(saved.closeAction || 'ask');
@@ -143,6 +148,16 @@ export const useSettingsStore = defineStore('settings', () => {
     downloadPath.value = p;
   }
 
+  function addLocalMusicPath(p: string) {
+    if (!localMusicPaths.value.includes(p)) {
+      localMusicPaths.value = [...localMusicPaths.value, p];
+    }
+  }
+
+  function removeLocalMusicPath(p: string) {
+    localMusicPaths.value = localMusicPaths.value.filter(v => v !== p);
+  }
+
   function setTheme(t: ThemeColor) {
     theme.value = t;
   }
@@ -170,6 +185,7 @@ export const useSettingsStore = defineStore('settings', () => {
   function resetAll() {
     audioQuality.value = 'standard';
     downloadPath.value = '';
+    localMusicPaths.value = [];
     theme.value = 'blue';
     appearance.value = 'dark';
     closeAction.value = 'ask';
@@ -178,10 +194,11 @@ export const useSettingsStore = defineStore('settings', () => {
     volume.value = 100;
   }
 
-  watch([audioQuality, downloadPath, theme, appearance, closeAction, shortcuts, outputDevice, volume], () => {
+  watch([audioQuality, downloadPath, localMusicPaths, theme, appearance, closeAction, shortcuts, outputDevice, volume], () => {
     const data: SettingsData = {
       audioQuality: audioQuality.value,
       downloadPath: downloadPath.value,
+      localMusicPaths: localMusicPaths.value,
       theme: theme.value,
       appearance: appearance.value,
       closeAction: closeAction.value,
@@ -195,6 +212,7 @@ export const useSettingsStore = defineStore('settings', () => {
   return {
     audioQuality,
     downloadPath,
+    localMusicPaths,
     theme,
     appearance,
     dataTheme,
@@ -204,6 +222,8 @@ export const useSettingsStore = defineStore('settings', () => {
     volume,
     setAudioQuality,
     setDownloadPath,
+    addLocalMusicPath,
+    removeLocalMusicPath,
     setTheme,
     setAppearance,
     setCloseAction,