feat: media player API, web player panel, and Hope music MCP

- web/media_server.py: FastAPI service owning the permanent library
  (library.json + ./media volume), yt-dlp YouTube Music search, queued
  download jobs with mp3 transcode (ffmpeg), per-room player desired
  state, and an HTTPS proxy for external live-stream URLs.
- agent/media_mcp.py: Hope tools — search_music, play_song,
  offer_song_choices, pause/resume/stop/skip/seek, now_playing,
  list_library, add_stream.
- agent/agent.py: media toolset wiring + conversation rule (music
  playing disables the agent mic; re-engaging pauses music).
- web UI: slide-out Music panel (search, suggestions, library, live
  stream add, play/pause, ±10s, seek, volume) with a reconciling poller
  and media_state data-channel reports.
- token server returns the minted room name; nginx serves /media/files
  as static (native Range) and proxies /media/api to the media server.
- supervisord runs media-server; compose mounts ./media and adds
  ffmpeg to the image.

.env.example

@@ -29,6 +29,19 @@ FIRECRAWL_BASE=http://192.168.86.2:3002
 # Per-user memory profiles and Bearer tokens live in config/users.json.
 VOICE_DEFAULT_USER=shane
 
+# ── Media player (music library + YouTube Music downloads) ─────────────────
+# The permanent library lives in ./media (bind-mounted to /data/media):
+#   media/files/  transcoded mp3 tracks
+#   media/thumbs/ cover art
+#   media/jobs/   download job status
+# MEDIA_SERVER_PORT=8092
+#
+# Optional: export cookies.txt from a browser logged into YouTube and drop it
+# in ./media/cookies.txt to avoid "confirm you're not a bot" download blocks.
+# Anonymous access works from most residential IPs; cookies are the reliable
+# path.
+# YTDLP_COOKIES=/data/media/cookies.txt
+
 # Extra MCP servers (optional). JSON list of {url, transport} objects.
 # transport: "sse" | "streamable_http" | omit for auto-detect
 # EXTRA_MCP_SERVERS=[{"url":"http://192.168.86.2:3001/mcp","transport":"streamable_http"}]