feat(hands-on): add guardrails rules lab and wire into docs

- New hands-on/rules/ interactive page: five toggleable rule sources
  (AGENTS.md, gate-discipline skill, Husky pre-commit, check-ui-contract
  enforcer, commitlint) rebuild a ruled prompt live against a naive prompt.
- Visual system mirrors hands-on/starter (same palette, vanilla JS).
- index.html hands-on section now links both labs.
- docs/operations-guide.md gains a 'Hands-on rules lab' subsection.
- README project structure lists the new lab.
- verify.mjs passes content, interaction, and standalone checks for both labs.

README.md

@@ -39,6 +39,8 @@ npm run verify
 - `docs/references/` — bundled research sources and notes
 - `docs/operations-guide.md` — canonical SilverBullet operations and skills guide
 - `hands-on/starter/` — dependency-free Tiny Tasks exercise
+- `hands-on/rules/` — dependency-free Guardrails lab; toggles rule sources into the prompt
+- `rules/` — bilingual case study of skills, CLI ratchets, Husky, and PR review
 - `GATES.md` — acceptance ledger for the project
 
 ## Publishing
@@ -63,3 +65,12 @@ Codex, and Git documentation. The [additional reading path](docs/references/addi
 bundles 12 verified articles and guides, including Medium and practitioner sources.
 See [model routing](docs/references/model-routing.md) for current provider controls
 and [verified skill sources](docs/references/skill-sources.md) for commit-pinned provenance.
+
+## Rules and enforcement case study
+
+Open `/rules/` for a concise walkthrough grounded in the
+`netcracker/interview` repository. It shows how `AGENTS.md`, project-local
+skills, machine-readable repo ledgers, a UI contract ratchet, lint-staged,
+Husky, commitlint, specialist verifier agents, and PR review reinforce one
+another. Every example links to its source file in Gitea, and the page includes
+a copy-ready prompt for mapping the same layers in another repository.