feat(operator): add queue-operator CRD reconciler with shard split/drain

Reconciles Queue CRs into Kafka topics + Redis shard-map/queue-meta state:
creates shard-0 on first reconcile, splits a shard's hash range into two
children once its split threshold is crossed, drains and closes a parent
shard once its consumer group has fully caught up and its retention
window has elapsed, and tears down every shard's topic + Redis state on
deletion. Includes the manager entrypoint (cmd/queue-operator) and RBAC.

config/rbac/role_binding.yaml

@@ -0,0 +1,12 @@
+apiVersion: rbac.authorization.k8s.io/v1
+kind: ClusterRoleBinding
+metadata:
+  name: queue-operator
+roleRef:
+  apiGroup: rbac.authorization.k8s.io
+  kind: ClusterRole
+  name: queue-operator
+subjects:
+  - kind: ServiceAccount
+    name: queue-operator
+    namespace: kmsvc