web-app-mediawiki: template-driven LocalSettings.php + admin automation; compose & config tweaks

Config & features:
- roles/web-app-mediawiki/config/main.yml:
  - Add sitename ('Wiki on {{ PRIMARY_DOMAIN | upper }}') and meta_namespace ('Meta')
  - Enable central_database feature and database service
  - Move volumes under docker.volumes (correct indentation)

Tasks & automation:
- roles/web-app-mediawiki/tasks/main.yml:
  - Avoid immediate compose handler flush (docker_compose_flush_handlers: false), then explicit meta: flush_handlers
  - Deploy templated LocalSettings.php to host path
  - Create admin via maintenance/createAndPromote.php (docker exec, idempotent changed_when/failed_when)

Templates:
- roles/web-app-mediawiki/templates/LocalSettings.php.j2:
  - Set $wgSitename, $wgMetaNamespace, $wgServer from MEDIAWIKI_*
  - DB settings (mysql, host:port, name, user, password)
  - Mail settings (EmergencyContact/PasswordSender)
  - Default skin: vector
  - Load basic extensions (ParserFunctions, Cite)
- roles/web-app-mediawiki/templates/docker-compose.yml.j2:
  - Switch to MEDIAWIKI_* vars, mount LocalSettings.php (ro)
  - Use container_port, include curl healthcheck
  - Fix volumes name to MEDIAWIKI_VOLUME

Vars:
- roles/web-app-mediawiki/vars/main.yml:
  - Restructure with MEDIAWIKI_* (sitename, meta_namespace, URL, image/version/container/volume)
  - Define SETTINGS host/dock paths, container_port, default user (www-data)
  - Admin bootstrap vars (name/password/email)

Misc:
- Add empty schema/main.yml placeholder for future validation

Refs: ChatGPT conversation (2025-08-28, Europe/Berlin). Link: https://chatgpt.com/share/68b0ace6-f8f4-800f-b7a7-a51a6c5260f1

roles/web-app-mediawiki/templates/docker-compose.yml.j2

@@ -1,16 +1,19 @@
 {% include 'roles/docker-compose/templates/base.yml.j2' %}
   application:
 {% include 'roles/docker-container/templates/base.yml.j2' %}
-      container_name: "{{ mediawiki_name }}"
-      image: "{{ mediawiki_image }}:{{ mediawiki_version }}"
-      volumes:
-        - "data:/var/www/html/"
-      ports:
-        - "127.0.0.1:{{ ports.localhost.http[application_id] }}:80"
+    container_name: "{{ MEDIAWIKI_CONTAINER }}"
+    image: "{{ MEDIAWIKI_IMAGE }}:{{ MEDIAWIKI_VERSION }}"
+    volumes:
+      - "data:/var/www/html/"
+      - "{{ MEDIAWIKI_SETTINGS_HOST_PATH }}:{{ MEDIAWIKI_SETTINGS_DOCK_PATH }}:ro"
+    ports:
+      - "127.0.0.1:{{ ports.localhost.http[application_id] }}:{{ container_port }}"
+{% include 'roles/docker-container/templates/healthcheck/curl.yml.j2' %}
 {% include 'roles/docker-container/templates/networks.yml.j2' %}
 {% include 'roles/docker-container/templates/depends_on/dmbs_excl.yml.j2' %}
 
 {% include 'roles/docker-compose/templates/volumes.yml.j2' %}
   data:
-    name: {{ mediawiki_volume }}
-{% include 'roles/docker-compose/templates/networks.yml.j2' %}
+    name: {{ MEDIAWIKI_VOLUME }}
+
+{% include 'roles/docker-compose/templates/networks.yml.j2' %}