feat: music library management, smooth fades, clickable URLs

- Audio-only downloads (-x), resume (-c), skip existing (--no-overwrites)
- Title-based filenames (e.g. never-gonna-give-you-up.opus)
- Separate cache (data/music/cache/) from kept tracks (data/music/)
- Kept track IDs: !keep assigns #id, !play #id, !kept shows IDs
- Linear fade-in (5s) and fade-out (3s) with volume-proportional step
- Fix ramp click: threshold-based convergence instead of float equality
- Clean up cache files for skipped/stopped tracks
- Auto-linkify URLs in Mumble text chat (clickable <a> tags)
- FlaskPaste links use /raw endpoint for direct content access
- Metadata fetch uses --no-playlist for reliable results

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

plugins/flaskpaste.py

@@ -114,7 +114,7 @@ def _create_paste(base_url: str, content: str) -> str:
         body = json.loads(resp.read())
     paste_id = body.get("id", "")
     if paste_id:
-        return f"{base_url}/{paste_id}"
+        return f"{base_url}/{paste_id}/raw"
     return body.get("url", "")