feat: YouTube customizable bitrate, improved title matching, SpotubeDL engine fallback

- Add configurable YouTube Opus (96-256kbps) and MP3 (96-320kbps) bitrates
- Improve title matching with loose normalization for symbol-heavy tracks
- Add SpotubeDL engine v2 fallback for MP3 requests
- Improve filename sanitization in track metadata screen
- Bump version to 3.6.9+82

pubspec.yaml

@@ -1,7 +1,7 @@
 name: spotiflac_android
 description: Download Spotify tracks in FLAC from Tidal, Qobuz & Amazon Music
 publish_to: "none"
-version: 3.6.7+81
+version: 3.6.9+82
 
 environment:
   sdk: ^3.10.0