feat(lyrics): add Netease Cloud Music as opt-in fallback source

Netease is queried only when server and LRCLIB both return nothing,
preserving the existing lyrics chain completely. Off by default.

- Rust command `fetch_netease_lyrics` proxies Netease API (CORS bypass)
- `src/api/netease.ts` TypeScript wrapper via invoke
- `authStore.enableNeteaselyrics` toggle (default: false)
- `useLyrics`: Netease fires last in fallback chain when enabled
- Settings toggle in the Lyrics section
- `lyricsSourceNetease` label in LyricsPane
- i18n: all 7 languages (en, de, fr, nl, nb, ru, zh)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/components/LyricsPane.tsx

@@ -57,7 +57,9 @@ export default function LyricsPane({ currentTrack }: Props) {
     ? t('player.lyricsSourceServer')
     : source === 'lrclib'
       ? t('player.lyricsSourceLrclib')
-      : null;
+      : source === 'netease'
+        ? t('player.lyricsSourceNetease')
+        : null;
 
   return (
     <div className="lyrics-pane">