Replaces the GCE VM runner with a k8s Deployment in the ci namespace on
neuron-platform GKE. Uses Docker-in-Docker for build isolation since
Autopilot doesn't expose the node socket. Runner token pulled from Secret
Manager via ESO + Workload Identity.
- servers/gcp/k8s/gitea-runner/: namespace, serviceaccount, external-secrets,
deployment manifests (ci namespace, dind sidecar, idempotent registration)
- servers/gcp/k8s/argocd-apps/gitea-runner-gke.yaml: Argo CD Application
- servers/gcp/gitea-runner.tf: gitea-runner-gke GCP SA with secretAccessor
on gitea-runner-token, Workload Identity binding for ci/gitea-runner,
artifactregistry.reader for pulling ci-base image
A single e2-standard-4 GCE VM in us-central1-a runs act_runner,
registered to git.neuralplatform.ai. Workload Identity Federation
binds the runner to the existing neuron-ci-pusher SA (artifactregistry.writer
+ run.developer + serviceAccountUser on the runtime SAs). No long-lived
JSON keys live on the runner; the GCP_SA_KEY secret remains as a fallback
in case the Gitea OIDC issuer isn't reachable from oauth2.googleapis.com.
The runner VM has its own minimal-scope SA (gitea-runner-vm) that can
only read the registration token from Secret Manager — splitting boot
identity from deploy identity so a runner compromise doesn't grant push.
SSH is IAP-only (no public ingress on :22). Reference workflow lives at
products/web/.gitea/workflows/deploy.yaml and takes manual gcloud out of
the loop: push to main triggers build, push to AR, parallel deploy to
all 3 marketing prod regions, traffic flip, smoke check.
Will Anderson