feat: add audio quality selector (standard to jymaster/Hi-Res)

- MusicProvider interface: setQuality/getQuality methods
- NeteaseProvider: passes quality level to /song/url/v1
- Default: exhigh (320kbps MP3)
- Settings page: 6-option grid selector
- GET/POST /api/music/quality endpoints

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/music/qq.ts

@@ -14,6 +14,7 @@ export class QQMusicProvider implements MusicProvider {
   readonly platform = "qq" as const;
   private api: AxiosInstance;
   private cookie = "";
+  private quality = "exhigh";
 
   constructor(baseUrl: string) {
     this.api = axios.create({
@@ -22,6 +23,14 @@ export class QQMusicProvider implements MusicProvider {
     });
   }
 
+  setQuality(quality: string): void {
+    this.quality = quality;
+  }
+
+  getQuality(): string {
+    return this.quality;
+  }
+
   private get cookieParams(): Record<string, string> {
     return this.cookie ? { cookie: this.cookie } : {};
   }
@@ -48,7 +57,7 @@ export class QQMusicProvider implements MusicProvider {
     return { songs, playlists: [], albums: [] };
   }
 
-  async getSongUrl(songId: string): Promise<string | null> {
+  async getSongUrl(songId: string, _quality?: string): Promise<string | null> {
     const res = await this.api.get("/getMusicPlay", {
       params: { songmid: songId, ...this.cookieParams },
     });