0402c408e4
- Add NextStatus type and prefetch state (nextStatus, nextAudioUrl, nextProgress, nextChapterPrefetched) to AudioStore - AudioPlayer triggers prefetchNext() when currentTime/duration >= 0.9, autoNext is on, and a next chapter exists - startPlayback() uses the pre-fetched URL if available (skipping presign round-trip and generation wait) - Auto-next button in layout shows a pulsing dot while prefetching and a green dot when ready - AudioPlayer shows inline prefetch progress and ready state below the controls - Fix indentation regression in layout onended handler