Update Headlamp and Vault documentation; enhance RBAC configurations in Argo CD. Modify Headlamp README to clarify sessionTTL handling and ServiceAccount permissions. Add Cilium network policy instructions to Vault README. Update Argo CD values.yaml for default RBAC settings, ensuring local admin retains full access while new users start with read-only permissions. Reflect these changes in CLUSTER-BUILD.md.

clusters/noble/apps/vault/README.md

@@ -22,6 +22,16 @@ kubectl -n vault get pods,pvc,svc
 kubectl -n vault exec -i sts/vault -- vault status
 ```
 
+## Cilium network policy (Phase G)
+
+After **Cilium** is up, optionally restrict HTTP access to the Vault server pods (**TCP 8200**) to **`external-secrets`** and same-namespace clients:
+
+```bash
+kubectl apply -f clusters/noble/apps/vault/cilium-network-policy.yaml
+```
+
+If you add workloads in other namespaces that call Vault, extend **`ingress`** in that manifest.
+
 ## Initialize and unseal (first time)
 
 From a workstation with `kubectl` (or `kubectl exec` into any pod with `vault` CLI):

clusters/noble/apps/vault/cilium-network-policy.yaml

@@ -0,0 +1,33 @@
+# CiliumNetworkPolicy — restrict who may reach Vault HTTP listener (8200).
+# Apply after Cilium is healthy: kubectl apply -f clusters/noble/apps/vault/cilium-network-policy.yaml
+#
+# Ingress-only policy: egress from Vault is unchanged (Kubernetes auth needs API + DNS).
+# Extend ingress rules if other namespaces must call Vault (e.g. app workloads).
+#
+# Ref: https://docs.cilium.io/en/stable/security/policy/language/
+---
+apiVersion: cilium.io/v2
+kind: CiliumNetworkPolicy
+metadata:
+  name: vault-http-ingress
+  namespace: vault
+spec:
+  endpointSelector:
+    matchLabels:
+      app.kubernetes.io/name: vault
+      component: server
+  ingress:
+    - fromEndpoints:
+        - matchLabels:
+            "k8s:io.kubernetes.pod.namespace": external-secrets
+      toPorts:
+        - ports:
+            - port: "8200"
+              protocol: TCP
+    - fromEndpoints:
+        - matchLabels:
+            "k8s:io.kubernetes.pod.namespace": vault
+      toPorts:
+        - ports:
+            - port: "8200"
+              protocol: TCP