Harden against bot floods and add post-provisioning service check

- Traefik rate-limits all routes (60 req/min standard, 300 for Nextcloud)
  and writes access logs to /var/log/traefik/access.log
- Fail2ban watches Traefik access logs and bans IPs after 10 x 403/404
  within 60 s for 24 h
- Nextcloud html directory created as www-data (UID 33) so Apache can
  process .htaccess and serve requests correctly
- scripts/check-services.sh verifies all seven endpoints return the
  expected HTTP status after provisioning

ansible/roles/nextcloud/tasks/main.yml

@@ -8,10 +8,20 @@
     mode: "0755"
   loop:
     - "{{ nextcloud_data_dir }}"
-    - "{{ nextcloud_data_dir }}/html"
     - "{{ nextcloud_data_dir }}/redis"
   tags: nextcloud
 
+# www-data inside the container is UID 33. The html directory must be owned by
+# this user so Apache can traverse it and process .htaccess files.
+- name: Create Nextcloud html directory (www-data UID 33)
+  ansible.builtin.file:
+    path: "{{ nextcloud_data_dir }}/html"
+    state: directory
+    owner: "33"
+    group: "33"
+    mode: "0755"
+  tags: nextcloud
+
 - name: Create Nextcloud database directory (postgres UID 999)
   ansible.builtin.file:
     path: "{{ nextcloud_data_dir }}/db"