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>

plugins/voice.py

@@ -38,6 +38,18 @@ _MAX_SAY_LEN = 500       # max characters for !say
 _WHISPER_URL = "http://192.168.129.9:8080/inference"
 _PIPER_URL = "http://192.168.129.9:5100/"
 
+
+def _find_voice_peer(bot):
+    """Find the voice-capable peer (the bot with 'voice' in only_plugins)."""
+    bots = getattr(bot.registry, "_bots", {})
+    for name, b in bots.items():
+        if name == bot._username:
+            continue
+        if getattr(b, "_only_plugins", None) and "voice" in b._only_plugins:
+            return b
+    return None
+
+
 # -- Per-bot state -----------------------------------------------------------
 
 
@@ -172,8 +184,10 @@ async def _flush_monitor(bot):
                     remainder = text[len(trigger):].strip()
                     if remainder:
                         log.info("voice: trigger from %s: %s", name, remainder)
-                        bot._spawn(
-                            _tts_play(bot, remainder), name="voice-tts",
+                        # Route TTS through voice-capable peer if available
+                        speaker = _find_voice_peer(bot) or bot
+                        speaker._spawn(
+                            _tts_play(speaker, remainder), name="voice-tts",
                         )
                     continue
 
@@ -242,10 +256,13 @@ async def _tts_play(bot, text: str):
     if wav_path is None:
         return
     try:
+        # Signal music plugin to duck while TTS is playing
+        bot.registry._tts_active = True
         done = asyncio.Event()
         await bot.stream_audio(str(wav_path), volume=1.0, on_done=done)
         await done.wait()
     finally:
+        bot.registry._tts_active = False
         Path(wav_path).unlink(missing_ok=True)