Voice page (connection tab):
- ListenControl baru: toggle Listen (Headphones) — mulai PcmPlayer dari
user gesture, subscribe onPcm WS, volume slider, bar level per-user
REAL dari PCM (bukan random).
- lib/audio/pcm-player.ts (baru): ScriptProcessorNode mixer — ring buffer
2s per user (hash FNV-1a sama dengan gateway), upsampling 24k→48k
linear, mix semua user ke mono, gain volume, cleanup ring diam 5s.
- useVoiceListen + hashUserId di hooks; auto-stop saat disconnect.
Recordings:
- recording-player: reset src+load+play() eksplisit (bukan autoPlay doang),
tampilkan filename + error state 'playback failed' kalau file rusak.
- recording-card: tombol Download fetch blob (CORS tele open) → objectURL
→ force download dengan nama asli; fallback buka tab baru kalau fetch
gagal; spinner saat mendownload.
Verified: FE tsc 0, next build 10/10 static pages.