[Priveetee]

Summary

• Move app updates out of About into their own Settings entry, with a status card, an update channel picker and formatted release notes.
• Recover playback when the server answers 404 for an idle SABR session it has evicted, instead of stopping on an error after a long pause.

Validation

• Android unit tests, lint, androidTest compilation and debug build passed.
• Checked the Updates screen in light and dark themes on a phone emulator (1080x2400), including an available update, a download and a failed verification.
• Reproduced the long-pause failure on a phone emulator against a test instance, then confirmed the fixed build opens a fresh session and keeps playing.
• Not tested on a physical phone.