Add the RndrSrvrDeviceAudioQualityChanged(27) renderer report end to end:
the report-type variant + message string in qconnect-protocol renderer.rs,
the RendererDeviceAudioQualityChangedMessage proto struct plus the genuinely
free tag-27 field on QConnectMessage (26=file AQ, 28=max AQ), and the mapper
arm. Wire the adapter emitter report_device_audio_quality_if_changed (deduped
via a new last_reported_device_audio_quality sync-state field) next to the
file-AQ report, sourcing the real output stream config. Fix the deferred-join
StateUpdated report to resolve the real current track duration (via CoreBridge)
and current/next queue_item_ids instead of hardcoding nulls.
cc