next() did `queue.slice(idx + 1)`, so the current track was always
queue[0]. prev()'s `idx > 0` guard could therefore never pass after an
auto-advance — Previous did nothing, ever — and repeat: 'all' jumped to
queue[0], which is the track that just finished, looping the last track of
an album instead of restarting it.
Replaced with a currentIndex cursor; the queue is no longer trimmed behind
the playhead. The old slice did serve a purpose — bounding Vibe-prefetch
growth — so that is preserved as a MAX_HISTORY = 50 cap that drops the
oldest entries and re-bases the index, rather than dropped outright.
setQueue/playTrack/setCurrentTrack recompute the cursor, next()/prev() fall
back to findIndex if it drifts, and shuffle now picks by index so the
cursor stays valid.
Consumer audit: NowPlayingPanel and Vibe.tsx already derived position via
findIndex and needed no change. TrackRow.handlePlay did
`setQueue(queue.slice(index))`, which re-broke prev at the point of click
even with the store fixed; it now passes the intact queue.
This commit also includes a pre-existing uncommitted fix from the working
tree (not authored by Claude): the end-of-queue auto-resume loop, which
stops playback at the end of the queue instead of restarting. It is correct
and independent of the cursor bug, and is preserved verbatim here.
REVIEW-2026-07-30.md finding 7.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
kami