feat(ansible): add Jellyfin service and improve deployment

- Add Jellyfin backend to HAProxy configuration on titania.incus
- Simplify deployment by using community.docker.docker_compose_v2 module
- Consolidate handlers and remove redundant Docker commands
- Update Jellyfin systemd service from oneshot to simple type
- Remove PUID/PGID environment variables from docker-compose template

ansible/jellyfin/docker-compose.yml.j2

@@ -26,8 +26,6 @@ services:
         syslog-address: "udp://prospero.incus:1514"
         tag: "jellyfin"
     environment:
-      - PUID={{ jellyfin_uid }}
-      - PGID={{ jellyfin_gid }}
       - TZ=America/Toronto
       - JELLYFIN_PublishedServerUrl={{ jellyfin_published_server_url }}
     extra_hosts: