Set DOCKER_HOST, DOCKER_TLS_VERIFY, DOCKER_CERT_PATH for k8s runner
DinD sidecar communication. Add 'until docker info' wait loop to
ensure daemon is ready before build starts.
Co-Authored-By: Claude <noreply@anthropic.com>
Build 3 muyu services (gateway, system-rpc, inventory-rpc)
as Docker images and push to Harbor registry.
Co-Authored-By: Claude <noreply@anthropic.com>