Nextcloud: integrate Talk & Whiteboard; adjust ports & healthchecks

- Enable Spreed (Talk); signaling via /standalone-signaling/
- STUN/TURN: move STUN to 3480 (3479 occupied by BBB), keep TURN 5350 reserved
- docker-compose: expose internal WS ports; explicit TURN port mapping
- Healthchecks: add nc-based TCP checks (roles/docker-container/templates/healthcheck/nc.yml.j2)
- Nginx: location proxy to talk:8081
- Schema: add talk_* secrets (turn/signaling/internal)
- Plugins: configure spreed/whiteboard via vars/*; remove old task files
- Ports matrix (group_vars/all/09_ports.yml) updated/commented

Conversation: https://chatgpt.com/share/68b61a6a-e1dc-800f-b793-4aa600bc0166

roles/web-app-nextcloud/config/main.yml

@@ -17,9 +17,7 @@ server:
         - "{{ WEBSOCKET_PROTOCOL }}://collabora.{{ PRIMARY_DOMAIN }}"
   domains:
     canonical:
-      nextcloud:    "cloud.{{ PRIMARY_DOMAIN }}"
-      talk:         "talk.{{ PRIMARY_DOMAIN }}"
-      whiteboard:   "whiteboard.{{ PRIMARY_DOMAIN }}"
+      - "cloud.{{ PRIMARY_DOMAIN }}"
 docker:
   volumes:
     data: nextcloud_data
@@ -242,7 +240,7 @@ plugins:
       - oidc_login  # Will be disabled
   spreed:
     # Nextcloud Spreed: offers video conferencing and chat functionalities (https://apps.nextcloud.com/apps/spreed)
-    enabled: false # @todo to activate it first implement web-svc-coturn and activate it
+    enabled: true
   tables:
     # Nextcloud tables: allows creation and editing of tables within the interface (https://apps.nextcloud.com/apps/tables)
     enabled: true