feat: playlist shuffle, lazy resolution, TTS ducking, kept repair

Music:
- #random URL fragment shuffles playlist tracks before enqueuing
- Lazy playlist resolution: first 10 tracks resolve immediately,
  remaining are fetched in a background task
- !kept repair re-downloads kept tracks with missing local files
- !kept shows [MISSING] marker for tracks without local files
- TTS ducking: music ducks when merlin speaks via voice peer,
  smooth restore after TTS finishes

Performance (from profiling):
- Connection pool: preload_content=True for SOCKS connection reuse
- Pool tuning: 30 pools / 8 connections (up from 20/4)
- _PooledResponse wrapper for stdlib-compatible read interface
- Iterative _extract_videos (replace 51K-deep recursion with stack)
- proxy=False for local SearXNG

Voice + multi-bot:
- Per-bot voice config lookup ([<username>.voice] in TOML)
- Mute detection: skip duck silence when all users muted
- Autoplay shuffle deck (no repeats until full cycle)
- Seek clamp to track duration (prevent seek-past-end stall)

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

TODO.md

@@ -130,6 +130,17 @@ is preserved in git history for reference.
 - [ ] SASL authentication
 - [ ] TLS/STARTTLS connection
 
+## Performance
+
+- [ ] Iterative `_extract_videos` in alert.py (51K recursive calls, 6.7s CPU)
+- [ ] Bypass SOCKS5 for local services (FlaskPaste, SearXNG)
+- [ ] Connection pool tuning (529 SOCKS connections per 25min session)
+- [ ] Async HTTP client (aiohttp + aiohttp-socks) to avoid blocking executors
+- [x] Connection pooling via urllib3 SOCKSProxyManager
+- [x] Batch OG fetch via ThreadPoolExecutor
+- [x] HTTP opener caching at module level
+- [x] Per-backend error tracking with exponential backoff
+
 ## Mumble
 
 - [x] Mumble adapter via TCP/TLS + protobuf control channel (no SDK)
@@ -144,9 +155,23 @@ is preserved in git history for reference.
 - [x] Configurable voice profiles (voice, FX chain)
 - [x] Self-mute support (auto mute/unmute around audio)
 - [x] Bot audio isolation (ignore own bots in sound callback)
+- [x] Pause/unpause with position tracking, stale stream re-download, rewind + fade-in
+- [x] Autoplay continuous radio (random kept track, silence-aware, configurable cooldown)
+- [x] Periodic resume state persistence (survives hard kills)
+- [x] Track duration in `!np` (ffprobe), optional `!announce` toggle
+- [x] Direct bot addressing (`merlin: say <text>`)
+- [x] Self-deafen on connect
 - [ ] Per-channel voice settings (different voice per channel)
 - [ ] Voice activity log (who spoke, duration, transcript)
 
+## Music Discovery
+
+- [ ] Last.fm integration (API key, free tier)
+- [ ] `!similar` command -- find similar artists/tracks via Last.fm
+- [ ] `!tags` command -- show genre/style tags for current track
+- [ ] Auto-queue similar tracks when autoplay has no kept tracks
+- [ ] MusicBrainz fallback (no API key, 1 req/sec rate limit)
+
 ## Slack
 
 - [ ] Slack adapter via Socket Mode WebSocket (no SDK)