- Decode received Opus audio: handle svxlink self-delimited framing and
provide monotonic PTS (c2.opus.decoder discards output when PTS == 0)
- Keep connection and playback alive in background via SvxService
(foreground service, media playback type)
- Keep screen on while app is open
- Show last talker callsign persistently instead of clearing after 4s
- Bump versionCode to 2, disable lint on release builds