docs: mark RBAC manifest as Flux-managed reference copy

- Remove rbac.authorization.k8s.io rule (create/delete on rolebindings
  was privilege escalation; no RBAC self-management needed)
- Remove self-applying kubectl apply step from e2e workflow
  (runner cannot grant its own permissions; RBAC must be pre-applied
  via Flux from infra repo)

Reviewed-by: Hugh Hackman

.github/workflows/e2e.yaml

@@ -100,4 +100,4 @@ jobs:
         with:
           name: test-results
           path: test-results/
-          retention-days: 7
+          retention-days: 7

deployment/e2e-ci-runner-rbac.yaml

@@ -0,0 +1,42 @@
+---
+# e2e-ci-runner-rbac.yaml
+#
+# Grants the GitHub Actions runner's service account (Arc Runners) the minimum
+# permissions needed to deploy/teardown an E2E Headlamp instance in the
+# privilegedescalation-dev namespace.
+#
+# RBAC is managed via Flux from privilegedescalation/infra — do not apply manually.
+# This manifest is a reference copy in the plugin repo.
+
+apiVersion: rbac.authorization.k8s.io/v1
+kind: Role
+metadata:
+  name: e2e-ci-runner
+  namespace: privilegedescalation-dev
+rules:
+  - apiGroups: [""]
+    resources: ["configmaps", "serviceaccounts", "events"]
+    verbs: ["get", "list", "create", "delete"]
+  - apiGroups: ["apps"]
+    resources: ["deployments"]
+    verbs: ["get", "create", "delete"]
+  - apiGroups: [""]
+    resources: ["services"]
+    verbs: ["get", "create", "delete"]
+  - apiGroups: [""]
+    resources: ["pods"]
+    verbs: ["get", "list"]
+---
+apiVersion: rbac.authorization.k8s.io/v1
+kind: RoleBinding
+metadata:
+  name: e2e-ci-runner
+  namespace: privilegedescalation-dev
+subjects:
+  - kind: ServiceAccount
+    name: runners-privilegedescalation-gha-rs-no-permission
+    namespace: arc-runners
+roleRef:
+  kind: Role
+  name: e2e-ci-runner
+  apiGroup: rbac.authorization.k8s.io