feat: add ReferenceGrant for cross-namespace routing

k8s/deployment.yaml

@@ -1,3 +1,17 @@
+apiVersion: gateway.networking.k8s.io/v1beta1
+kind: ReferenceGrant
+metadata:
+  name: allow-kube-system-to-default
+  namespace: default
+spec:
+  from:
+  - group: gateway.networking.k8s.io
+    kind: HTTPRoute
+    namespace: kube-system
+  to:
+  - group: ""
+    kind: Service
+---
 apiVersion: v1
 kind: ServiceAccount
 metadata: