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/base/files/filter.d/traefik.conf

@@ -0,0 +1,6 @@
+[Definition]
+# Matches Traefik CLF access log lines where the response status is 403 or 404.
+# Banning on these two codes catches vulnerability scanners (403) and path probers (404)
+# without touching legitimate 401 auth challenges or 429 rate-limit responses.
+failregex = ^<HOST> \S+ \S+ \[.*?\] ".*?" (?:403|404) .*$
+ignoreregex =

ansible/roles/base/files/jail.d/traefik.conf

@@ -0,0 +1,8 @@
+[traefik]
+enabled  = true
+port     = http,https
+filter   = traefik
+logpath  = /var/log/traefik/access.log
+maxretry = 10
+findtime = 60
+bantime  = 86400

ansible/roles/base/handlers/main.yml

@@ -3,3 +3,8 @@
   ansible.builtin.service:
     name: ssh
     state: restarted
+
+- name: Restart fail2ban
+  ansible.builtin.service:
+    name: fail2ban
+    state: restarted

ansible/roles/base/tasks/main.yml

@@ -126,6 +126,26 @@
 
 # --- Fail2ban ---
 
+- name: Deploy fail2ban filter for Traefik
+  ansible.builtin.copy:
+    src: filter.d/traefik.conf
+    dest: /etc/fail2ban/filter.d/traefik.conf
+    owner: root
+    group: root
+    mode: "0644"
+  notify: Restart fail2ban
+  tags: base
+
+- name: Deploy fail2ban jail for Traefik
+  ansible.builtin.copy:
+    src: jail.d/traefik.conf
+    dest: /etc/fail2ban/jail.d/traefik.conf
+    owner: root
+    group: root
+    mode: "0644"
+  notify: Restart fail2ban
+  tags: base
+
 - name: Enable and start fail2ban
   ansible.builtin.service:
     name: fail2ban