Observe agent guardrails on a real PR, then port to PingStep

Agent guardrails were built on this repo on 2026-08-21. Layers 1-3 are in place; what remains is proving them on a genuine pull request and porting them to PingStep.

Shipped

• .github/workflows/protected-paths.yml - fails a PR when tests, workflows, audit scripts or .test-count change without an approved-test-change label
• scripts/audit-test-floor.mjs + .test-count (baseline 89) - a floor that only rises
• .claude/settings.json - deny rules on the same paths
• wired into npm run verify and deploy-pages.yml

Negative test passed locally. Removing one Worker test dropped the count to 88 and the floor exited 1 with a clear message; restoring returned it to 89 and exit 0.

Outstanding

• Create the approved-test-change label, or the guard can never be satisfied
• Open one real pull request. protected-paths.yml only runs on pull_request, so pushes straight to main never exercise it
• Decide the bot-identity question. CODEOWNERS plus required review does not work for a solo maintainer because GitHub blocks self-approval; it becomes a real gate only if the agent commits under a separate identity
• Port to PingStep, where agent changes are least read

Known limit. The floor counts tests, it does not judge them. An assertion weakened in place keeps the count at 89 and passes. Only the review gate catches that.

Then write the technical article "Stop the agent editing its own tests" with real evidence, and narrow the illustrative-examples caveat in the published note.

Detail: docs/BACKLOG.md BL-1
Related: https://mantoshkumar1.github.io/insights/make-the-banks-deterministic.html

Start with .github/workflows/protected-paths.yml, scripts/audit-test-floor.mjs, .test-count, .claude/settings.json, and docs/BACKLOG.md entry BL-1. Open a genuine pull request to exercise the workflow, then investigate the PingStep integration and bot-identity decision. Done means the label exists, the PR gate runs with real evidence, PingStep is covered, and the technical article is updated.