Add Redis readiness check before Nextcloud upgrade and add retry logic for maintenance repair

This prevents OCC repair failures caused by Redis still loading its dataset after container restarts.
See context: https://chatgpt.com/share/690377ba-1520-800f-b8c1-bc93fbd9232f

roles/web-app-nextcloud/tasks/03_upgrade.yml

@@ -7,6 +7,9 @@
   command: "{{ NEXTCLOUD_DOCKER_EXEC_OCC }} maintenance:repair --include-expensive"
   register: occ_repair
   changed_when: "'No repairs needed' not in occ_repair.stdout"
+  retries: 3
+  delay: 10
+  until: occ_repair.rc == 0
 
 - name: Nextcloud | App update (retry once)
   command: "{{ NEXTCLOUD_DOCKER_EXEC_OCC }} app:update --all"

roles/web-app-nextcloud/tasks/main.yml

@@ -16,6 +16,13 @@
 - name: Flush all handlers immediately so that occ can be used
   meta: flush_handlers
 
+- name: Wait until Redis is ready (PONG)
+  command: "docker exec {{ NEXTCLOUD_REDIS_CONTAINER }} redis-cli ping"
+  register: redis_ping
+  retries: 60
+  delay: 2
+  until: (redis_ping.stdout | default('')) is search('PONG')
+
 - name: Update\Upgrade Nextcloud
   include_tasks: 03_upgrade.yml
   when: MODE_UPDATE | bool