When Calico shuts down on a flock-labeled node, calico-node sets
NetworkUnavailable=True with reason CalicoIsDown. Nothing replaces it,
so kubelet's NodeController applies node.kubernetes.io/network-
unavailable:NoSchedule and new pods can't land.
flock-agent now patches Status.Conditions every 60s with
NetworkUnavailable=False (reason=FlockReady). RBAC: nodes/status patch.
Co-Authored-By: Claude Sonnet 4.6 (1M context) <noreply@anthropic.com>