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/inventory/host_vars/titania.incus.yml

@@ -74,6 +74,12 @@ haproxy_backends:
     backend_port: 22084
     health_path: "/api/ping"
 
+  - subdomain: "jellyfin"
+    backend_host: "rosalind.incus"
+    backend_port: 22086
+    health_path: "/health"
+    timeout_server: 300s
+
   - subdomain: "arke"
     backend_host: "sycorax.incus"
     backend_port: 25540