fix: prevent music canplay callback from interrupting ABS playback start

When absPlayItem() paused S.audio, the stale canplay listener from the
last playCurrent() call still had a matching _playGen value and would
call S.audio.play() — triggering absInterrupt() which immediately paused
the ABS audio. Fix: export cancelMusicAutoplay() that bumps _playGen
before pausing, invalidating any pending canplay/guard callbacks.

Also shrink OK button and widen time input in sleep timer.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/player.js

@@ -433,6 +433,10 @@ export function _syncNpDirect(s) {
   syncNpStar();
 }
 
+// Bump _playGen so any stale canplay/guard callbacks from the last playCurrent()
+// bail out and don't call S.audio.play() after ABS has taken over audio.
+export function cancelMusicAutoplay() { _playGen++; S.audio.pause(); }
+
 // ─── TRANSPORT ────────────────────────────────────────────────────────────
 
 export function togglePlay() {