Remove SkillGym suite and repo-health snapshot infrastructure

[thymikee]

Removes the SkillGym suite and the repo-health snapshot per the 2026-07-28 descope recorded on #1412: two parallel LLM-judge suites answered one question (the help-conformance bench is now the single non-gating small-model oracle), and the observatory track is deferred until a concrete consumer exists (#1424 and PR #1477 closed).

Summary

• SkillGym removed end-to-end (test/skillgym/, 770 LOC + config): the smoke suite, runner environment, local-cli-help-policy helpers, and the bin/agent-device wrapper. The test:skillgym* package scripts and the skillgym devDependency are gone (lockfile regenerated), along with the .skillgym-results/ entries in .gitignore/.oxfmtrc.json, the unit-lane include in vitest.config.ts, and the fallow config globs + stale fallow-baselines/health.json entry.
• check-affected simplified: the skillgym check id, catalog entry, and ownership rule are removed. Behavior change: skills/*.md now classifies as docs-only in the selector — previously it selected the SkillGym suite; without an owning suite it would otherwise fail open to the full check set on every SKILL.md edit.
• scripts/repo-health removed (~1.2k LOC, 6 files). Forced by the descope and by this diff: repo-health/run.ts statically imported the deleted SkillGym suite. Its only gating assertion duplicated the Layering Guard job, and its sole planned consumer (obs: evolve the size-report PR comment into a quiet quality-delta comment + metric history on main #1424 / PR obs: quiet quality-delta PR comment + repo-health metric history on main #1477) is closed. The depgraph/layering models remain the queryable data. Also drops the now-consumerless SLOW_TEST_RATCHET re-export from scripts/vitest-slow-test-budgets.ts and two stale comments pointing at repo-health (scripts/layering/check.ts, budgets module).
• Docs updated to route command-planning guidance checks at the help-conformance bench instead: AGENTS.md, docs/agents/testing.md, docs/agents/pull-requests.md, test/output-economy/README.md, test-app README + one fixture comment.

Validation

Local: oxfmt --check, oxlint, tsc, check:layering (all R-rules green, R6 at 7, R9 at 102), fallow audit --base origin/main (no issues in the 33 changed files), the check-affected node --test suites (31/31), and the full unit run (unit-core + subprocess-stub, 4,700+ tests, exit 0; two tests over budget inside the 2x load-variance band, non-failing). Build/smoke lanes left to CI — the diff is tooling/docs-only outside examples/test-app/src/screens/FormScreen.tsx, which changes a comment.

🤖 Generated with Claude Code

https://claude.ai/code/session_01FUv7bvbWNryuXgSBuqTtep

[github-actions]

PR Preview Action v1.8.1
Preview removed because the pull request was closed.
2026-07-29 09:46 UTC

[github-actions]

Size Report

Metric	Base	Current	Diff
JS raw	1.87 MB	1.87 MB	0 B
JS gzip	602.8 kB	602.8 kB	0 B
npm tarball	720.6 kB	720.5 kB	-93 B
npm unpacked	2.52 MB	2.52 MB	-499 B

Startup median (7 runs, lower is better):

Scenario	Base	Current	Diff
CLI --version	30.0 ms	29.3 ms	-0.6 ms
CLI --help	60.3 ms	59.8 ms	-0.5 ms

Top changed chunks: no changes in the largest emitted chunks.

[thymikee]

Two P2 cleanup findings remain at bced9062:

1. docs/agents/testing.md still says every skills/ change requires pnpm format and describes formatting as always-on, while selectChecks() now short-circuits skills/*.md as docs-only with checks: [] and the updated regression pins that behavior. Make the matrix/narrative match the intentional no-local-check policy, or retain format selection.

2. The merge result still leaves examples/README.md saying test-app is used for SkillGym experiments, contradicting the claimed end-to-end removal; update that root examples index too.

The #1412/#1424 descope and removal wiring otherwise look coherent. Completed exact-head gates are green; iOS Smoke is still in progress. No ready-for-human label until these are resolved.

[thymikee]

Both P2 findings addressed in ca50809 (which also merges current main so the fix applies to the merge result):

1. Docs now state the intentional docs-only policy rather than retaining format selection: the Testing Matrix row says skills/ is Markdown-only guidance that oxfmt ignores (**/*.md) and the selector classifies docs-only. The claim was a no-op even before the descope — oxfmt never formatted skills Markdown — so the matrix was describing a gate that didn't exist. formatGate drops the dead underSkills fact so the code stops making the same stale claim (oxfmt covers src/ and test/).
2. examples/README.md (merged in via feat(examples): add runnable Node.js SDK examples under examples/sdk/ #1469, which is why the branch-side sweep missed it) loses its skillgym mention.

Selector node --test suites (31/31), oxfmt, oxlint, tsc (incl. the new examples/sdk project), fallow audit vs merge result, and check:production-exports all green locally.

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Generated by Claude Code

[thymikee]

Re-reviewed the current head ca50809 after the follow-up fixes. No remaining findings from me.

The two earlier P2s are resolved in the merge result: the skills/*.md docs-only policy is now consistent between the selector, regression test, and testing guide, and the last stale SkillGym mention in examples/README.md is gone. I also checked the removal wiring and stale references for SkillGym, repo-health, and the extracted slow-test budget module; the remaining SkillGym occurrence is only the explanatory selector comment.

Focused validation: pnpm check:affected:test passes 31/31 locally. Exact-head CI is fully green, including Fallow Code Quality, coverage, integration, iOS/Android/macOS/Linux smoke, and Web Platform Smoke. This matches the #1412/#1424 descope and looks ready to merge.