Document LiveKit JWT Service reaching LiveKit Server via the public URL

Also enable WebSocket support in the Nginx Proxy Manager example,
which LiveKit Server requires.

Fixes https://github.com/spantaleev/matrix-docker-ansible-deploy/issues/5484

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

docs/configuring-playbook-matrix-rtc.md

@@ -44,6 +44,8 @@ If you're [fronting the integrated reverse-proxy webserver with another reverse-
 
 See [`examples/reverse-proxies/nginx/matrix.conf`](../examples/reverse-proxies/nginx/matrix.conf) for an nginx example.
 
+[LiveKit JWT Service](configuring-playbook-livekit-jwt-service.md) also reaches LiveKit Server via its public URL (`https://matrix.example.com/livekit-server/`), so the Matrix server itself must be able to reach it through your other reverse-proxy. Otherwise, calls fail with `Unable to create room on SFU`.
+
 ## Installing
 
 After configuring the playbook and potentially [adjusting your DNS records](#adjusting-dns-records) and [adjusting firewall rules](#adjusting-firewall-rules), run the playbook with [playbook tags](playbook-tags.md) as below:

examples/reverse-proxies/nginx-proxy-manager/README.md

@@ -32,6 +32,8 @@ Domain Names: matrix.example.com
 Scheme: http
 Forward Hostname/IP: IP-ADDRESS-OF-YOUR-MATRIX
 Forward Port: 81
+# Required for Matrix RTC (LiveKit Server)
+Websockets Support: true
 
 # SSL
 # Either 'Request a new certificate' or select an existing one