feat(web-app-drupal): add Drupal role, OIDC config, and wiring

- networks: add web-app-drupal subnet 192.168.104.80/28
- ports: map localhost http port 8060
- add role files: tasks, vars, schema, users, templates (Dockerfile, docker-compose, settings.local.php, upload.ini)
- add docs: README.md and Administration.md

Ref: https://chatgpt.com/share/690535c5-b55c-800f-8556-5335a6b8a33f

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

@@ -0,0 +1,37 @@
+title:                "Site"
+max_upload_size:      "256M"
+features:
+  matomo:             true
+  css:                false
+  desktop:            true
+  oidc:               true
+  central_database:   true
+  logout:             true
+server:
+  csp:
+    flags: {}
+    whitelist: {}
+  domains:
+    canonical:
+      - "drupal.{{ PRIMARY_DOMAIN }}"
+    aliases: []
+docker:
+  services:
+    database:
+      enabled:            true
+    drupal:
+      version:            latest
+      image:              drupal
+      name:               drupal
+      backup:
+        no_stop_required: true
+  volumes:
+    data:                 drupal_data
+rbac:
+  roles:
+    authenticated:
+      description: "Logged-in user"
+    content_editor:
+      description: "Can create and edit content"
+    site_admin:
+      description: "Full site administration"