Two bugs in the audio handler caused the playback issues seen on the
v2026.05.13.0 build:
1. **Queue button on the now-playing screen did nothing.** MinstrelAudio
Handler never overrode skipToQueueItem, so taps in QueueScreen fell
through to BaseAudioHandler's empty default. The queue UI updated
nothing because the handler did nothing. Now overridden: rebuilds
the source list via setQueueFromTracks(_lastTracks, initialIndex)
so the targeted item plays cleanly even when its source hadn't been
built yet by the background fill.
2. **Tapping a song in a playlist let the previous track bleed through
until the new source finished building.** setQueueFromTracks awaits
_buildAudioSource before swapping the player's source list, and
that wait can be a few hundred ms on a cache miss. During the wait
the old source kept playing while the mini player UI had already
flipped to the new title/artist. Now pause()ing the player at the
start of setQueueFromTracks silences the old source the moment the
user taps.
Also stashes the most recent TrackRef list as _lastTracks so
skipToQueueItem can reconstruct sources without having to peek into
just_audio's internal source list.
bvandeusen
3e7b2582a2