Enhance Headlamp's metrics access by updating the ClusterRoleBinding to include permissions for metrics.k8s.io, nodes, and CustomResourceDefinitions. Update README and RBAC documentation to clarify OIDC user permissions and troubleshooting steps for metrics visibility issues.

clusters/noble/bootstrap/headlamp/README.md

@@ -38,6 +38,10 @@ Headlamp logs like **“Request completed successfully”** for **`/plugins`** o
 3. **API server logs** often spell out the failure (**invalid bearer token**, wrong **audience**, unknown **issuer**). Check **`kube-apiserver`** logs on a control-plane node if steps 1–2 look correct.
 4. **`oidc: email not verified`**: with **`oidc-username-claim: email`**, the API server rejects **`email_verified: false`**. Either set **`oidc-username-claim`** to a non-email claim (this repo uses **`preferred_username`** in **`talos/talconfig.yaml`**) or make Authentik issue **`email_verified: true`** for that user.
 
+## OIDC: no nodes, no CPU/memory, plugins misbehave
+
+In-cluster Headlamp calls the API **as your OIDC user**, not as the **headlamp** ServiceAccount. The built-in **`edit`** role does not cover **`metrics.k8s.io`** or cluster **nodes**. Re-apply **`kubectl apply -k clusters/noble/bootstrap/headlamp`** so **`metrics-clusterrolebinding.yaml`** stays current: it binds **`noble-admins`** to **`headlamp-metrics-reader`**, which adds metrics, **nodes**, and read-only **CustomResourceDefinitions** (helps many plugins). Ensure **metrics-server** (or equivalent) is installed. If the plugin marketplace never loads, check the browser network tab for blocked HTTPS requests to external hosts.
+
 To use another duration (cluster `spec.serviceAccount` / admission limits may cap it):
 
 ```bash