Previously `docker image prune -af --filter until=72h` only removed
images older than 72h. With multiple deploys/day we accumulate many
fresh (<72h) tagged images — each gendesign-backend / worker / frontend
SHA-tag is 500MB-1GB, filling /var/lib/docker.
New logic: for each ghcr.io/lekss361/gendesign-* repo, list tags sorted
by Created DESC, skip :latest, keep top 2, remove the rest. Still runs
the standard prune after for dangling layers + build cache.
9658baa6b2