A play can take seconds before audio starts (esp. Plex, whose resolve downloads
the whole file) with no feedback today. Add a source-agnostic loading indicator:
- A loading flag keyed to PENDING_PLAY_ID, raised at the top of play_audible
(before the Plex/Qobuz/local resolve — single chokepoint, covers auto-advance)
and cleared by the poll loop when the requested track's audio actually starts
(position > 0). Cleared on every play-error early-return and force-cleared on
queue-finished / peer-controller / ephemeral-stop so it never sticks.
- Watchdog: force-clear after 45s if the engine accepted a play that silently
never advances (undecodable-but-valid file) — otherwise the spinner is eternal.
- Spinner on three surfaces driven by NowPlayingState.loading: now-playing bar
(cover overlay + play/pause button), the active track row's play cell, and the
album big play button (gated to the album actually being launched).
Audio backend / playback routing untouched. The spinner only communicates the
wait; the underlying Plex fetch latency is fixed separately (progressive streaming).
cc
vicrodh
ed7891c697