docs(tst-30): second runner gitea-runner-2 live; close operator action

docs/runbooks/TST-30-second-ci-runner.md

@@ -1,5 +1,24 @@
 # TST-30 — Register A Second CI Runner (Operator Runbook)
 
+> **Executed 2026-08-07 — option (a) shipped; this runbook is now history plus the one
+> correction below.** `gitea-runner-2` (runner id 5, capacity 2, labels `ubuntu-latest`/
+> `ubuntu-22.04`) runs on `10.100.0.35` from the `/opt/gitea` compose stack with the same
+> `container.network: traefik` setting as the original; its registration token is mounted from a
+> `0600` file rather than inlined in compose. The existing `gitea-runner` (id 1, capacity 4) was
+> left untouched, so capacity went 4 → 6 by addition and the change reverts by removing one
+> container. Concurrency was verified by pushing HEAD to two scratch branches while an unrelated
+> run was in flight: jobs from three runs ran simultaneously across both runners, and a
+> `gitea-runner-2` job cloned successfully from `http://gitea:3000` (the property option (c) was
+> rejected for losing).
+>
+> **Correction to the Verification and Done-criteria sections below:** they expect
+> `GET /repos/dohertj2/mxaccessgw/actions/runners` to show ≥2 runners. It does not — it still
+> returns `total_count: 0`, correctly, because both runners are registered at the **instance**
+> level, which is the very condition the "Why" section describes. Use
+> `GET /api/v1/admin/actions/runners` instead (it lists id 1, id 4 — an unrelated local macOS
+> runner — and id 5). For per-job runner attribution, `GET /repos/{owner}/{repo}/actions/runs/{id}/jobs`
+> exposes `runner_id`/`runner_name` on each job; the `actions/tasks` listing does not.
+
 Operator steps to relieve the single shared Gitea Actions runner that CI depends on. The
 repo-side half of TST-30 (documenting the shared-runner/no-cancel reality and the
 `run-windev-ci.sh` bypass) is already landed in `docs/GatewayTesting.md`; registering the