Replaces the Part 0 probe workflow, whose four measurements are recorded in
documentation/audits/SPIKE-ci-runner-2026-08-02.md.
Reports, does not refuse: pushes go straight to main with no pull request, so there is no
merge for a status check to stand at. The refusing half is .githooks/pre-push, which is
per-clone and --no-verify-able; this half notices when that was skipped.
No uses: step anywhere — JavaScript actions need a node runtime the host-mode runner does
not have. Probe P3 measured that a shallow git fetch of the exact pushed SHA from the
in-cluster Gitea service is sufficient, and that it equals the pushed commit.
The alarm step is deliberately absent until probe P5 measures whether Gitea already mails
on a failed run.
