Catch COMMAND_FAILED/NOT_INITIALIZED in PlayerNative.seek() and
PlayerAndroid.seek() directly, preventing unhandled PlatformException
crashes on macOS app resume. Remove the ~200-line
_PendingSeekCoordinator system and revert all callsites to direct
player.seek(clampSeekPosition(...)). Keep seekable property/stream
and media controls gating. Add ExoPlayer seekable emission.