- Concatenate all paragraphs + transition hint into one TTS call per slide
→ natural prosody, zero gaps within a slide
- Pre-fetch next slide's audio during current playback → seamless transitions
- Advance slide during transition phrase ("Let us look at...")
- Pause/resume without destroying audio → instant continue
- Subtitle display synced to playback position via timeupdate
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>