feat: drop blanket recreates, ACME-DNS knobs, notify_push override

- Drop `recreate: always` from collabora/drawio/homarr/opencloud/traefik
  handlers and the authentik_outpost_ldap start task. `up -d` with
  `state: present` already recreates exactly the services whose
  compose definition changed; the blanket recreate was forcing
  restarts even when nothing relevant moved.
- Rewrite the `*_domains` Traefik Host loop to the `Host(\`a\`) ||
  Host(\`b\`)` form across authentik/collabora/garage/nextcloud so the
  rule still matches when traefik can't normalize the comma-form into
  the same canonical shape.
- Traefik: add `traefik_acme_tcp_only` (sets LEGO_EXPERIMENTAL_DNS_TCP_ONLY)
  and `traefik_acme_disable_ans_checks` (disables lego's authoritative-NS
  propagation check) for environments where the DNS path between the
  traefik container and the zone's nameservers is constrained.
- Traefik DMZ collector: two-step merge so a `traefik_dmz_exposed_services`
  entry that sets its own `backend_host` wins over the host fallback;
  lets a route target an internal FQDN covered by the backend cert's
  SANs instead of the raw IP.
- Nextcloud: add `nextcloud_notify_push_domain` override for the
  `occ notify_push:setup` call so the setup check can hit an internal
  FQDN instead of hairpinning through the DMZ. Push router now matches
  every entry in `nextcloud_domains`.
- Nextcloud: also %2F-escape slashes in the postgres user/password
  inside the notify_push DATABASE_URL.

roles/traefik/tasks/main.yml

@@ -9,7 +9,18 @@
 
 - name: Build service registry from backend servers (DMZ mode)
   set_fact:
-    proxied_services: "{{ proxied_services | default([]) + hostvars[item].traefik_dmz_exposed_services | default([]) | map('combine', {'backend_host': hostvars[item].ansible_host | default(item)}) | list }}"
+    # Two-step merge so a service entry's own `backend_host` wins:
+    # entries that set it pass through unchanged, entries that don't
+    # get the backend host's ansible_host as fallback. The override
+    # lets a route target an internal FQDN covered by the backend
+    # cert's SANs instead of the raw IP (which would fail backend
+    # TLS verification at the proxy hop).
+    proxied_services: >-
+      {{
+        proxied_services | default([])
+        + (hostvars[item].traefik_dmz_exposed_services | default([]) | selectattr('backend_host', 'defined') | list)
+        + (hostvars[item].traefik_dmz_exposed_services | default([]) | rejectattr('backend_host', 'defined') | map('combine', {'backend_host': hostvars[item].ansible_host | default(item)}) | list)
+      }}
   loop: "{{ _backend_servers | default([]) }}"
   when: traefik_mode == 'dmz'