TSIG keys were included in every cluster's keys.conf namespace-wide. When
multiple clusters share a namespace, that leaks keys across clusters. Add
spec.clusterRef so a key can target a specific BindCluster; empty keeps
the shared (all-clusters-in-namespace) behaviour.
- api: BindTSIGKey.spec.clusterRef (optional)
- BindCluster keys.conf now includes only keys with matching or empty
clusterRef
- regenerate CRDs + install.yaml bundle