Alpha release for Light Phone III testers.\n\nChanges since alpha3:\n- Adds folder-based multi-file local audiobooks with alphabetical, continuous playback and one combined timeline.\n- Adds native Android media-session support for Bluetooth, vehicle, and LightOS playback controls.\n- Keeps paused LightOS media controls available without retaining an unnecessary foreground service.\n- Improves Libby player-frame reconnection when returning from Local or RSS playback.\n- Includes local timeline and media-session mapping tests.\n\nBard remains alpha software. Existing Libby, Local, and RSS limitations documented in the README still apply.