acc7149537
CI fixes: - artist_detail_screen.dart: drop unnecessary foundation import (debugPrint comes from material) and unused metadata_prefetcher import. Playback timing visibility (so we can stop guessing where the lag lives): - playTracks now logs serverUrl / token / configure / setQueue / play() returned, each stage in milliseconds. The next time you tap play, we'll see exactly where the seconds go. - setQueueFromTracks adds two more measurements: total source-build time across all tracks, and setAudioSources duration. Small concrete win: - audio_handler caches the application cache dir path on first use (already cached in _maybeRegisterStreamCache; now also used in _buildAudioSource for the LockCachingAudioSource path). One less platform channel hit per track on cache-miss queue builds. Once we see real numbers we can decide whether the fix is to build sources lazily (initial source first → play → background-add the rest), pre-warm the audio handler at app start so playTracks skips serverUrl + token reads entirely, or something else.