- Convert `renderer_event_to_payload` and `media_server_sse::event_handler`s to async
- Replace sync cover URL transformation with `.await` on `transform_cover_url`
- Remove blocking thread-based workarounds for async execution
- Improve SSE scalability and responsiveness by eliminating nested runtimes
- Implement new /covers/proxy endpoint to cache and rewrite external LAN cover URLs
- Add url/urlencoding dependencies for URL parsing/escaping in pmocontrol and pmocovers Cargo.toml
- Transform album_art_uri fields to use proxy endpoint for LAN URLs in REST and SSE handlers (browse_container, MetadataChanged)
- Add URL validation logic to detect LAN vs public URLs and avoid self-caching
- Update Cargo.lock with new dependencies
- Ajout d'un BaseUrl layer dans pmoserver pour gérer les URLs absolues (LAN/WAN)
- Renommage de `covers_absolute_url_for` → ` covers_relative_route`, stocker les routes relatives
- Mise à jour des appels UPnP vers `covers_absolute_url_for_upnp` (fallback PMO_SERVER_URL)
- Correction des tâches de fond pour stocker les routes, pas l'URL complète
- Suppression du feature gate `simd` inutilisé dans pmoaudio/src/lib.rs
