Linthra 0.1.11 — folder browsing and Android navigation.

- Browse Jellyfin and Navidrome/Subsonic through their real folder hierarchy from Library → Folders.
- Open nested folders and start songs directly from the folder view.
- Android Back now closes internal states, returns from detail screens, goes back to Library from other main tabs, and exits only from Library root.
- No ads, tracking, analytics, or telemetry.
