diff --git a/apps/github-runner/github-runner.yaml b/apps/github-runner/github-runner.yaml
index aa3ca00..826625b 100644
--- a/apps/github-runner/github-runner.yaml
+++ b/apps/github-runner/github-runner.yaml
@@ -233,7 +233,13 @@ metadata:
     app.kubernetes.io/managed-by: argocd
     flowercore.io/created-by: argocd
 spec:
-  replicas: 1
+  # PARKED 2026-05-21: scaled to 0. The Shared.Pos build still fails on the
+  # non-root runner (actions/setup-dotnet -> /usr/share/dotnet denied); a
+  # churning ephemeral runner just retries a doomed build and drives HighCPU
+  # on rke2-agent2. Re-enable (replicas: 1) only as part of the Sprint 30+
+  # Cx-1 Linux-runner-fleet lane, which sets DOTNET_INSTALL_DIR on the runner
+  # pod env fleet-wide. See memory/feedback_flip_sweep_nonroot_runner_workflow_fallout.
+  replicas: 0
   selector:
     matchLabels:
       app.kubernetes.io/name: github-runner-sharedpos