When the pull-through proxy (10.0.20.10) is down, containerd now falls
back to the official upstream registries (registry-1.docker.io, ghcr.io)
instead of failing. Also cleans up stale disabled registry mirror dirs
and removes unnecessary containerd restart from the rollout script.
Replace deprecated wildcard containerd mirror with per-registry
config_path approach. Add proxy containers for ghcr.io, quay.io,
registry.k8s.io, and reg.kyverno.io on the docker-registry VM.
Set static IP for docker-registry VM to avoid DHCP issues.
