[BUG]: Nextcloud deployment has no liveness probe for php-fpm container

**Actual:**

Liveness probes are only configured for the nginx container, but not for `php-fpm` so php hangups are not correctly recognized.

**Desired:**

Implement liveness probes for php-fpm. We could add a custom shell script to the container and execute it for the liveness e.g.: https://github.com/renatomefi/php-fpm-healthcheck#kubernetes-example

Locate the Nextcloud deployment manifest and the php-fpm container definition, then compare its health configuration with the existing nginx liveness probe. Review the referenced php-fpm-healthcheck Kubernetes example and verify that the resulting probe detects php-fpm hangups without disrupting healthy containers.

Written by the indexing model from the issue text.