Fix a failing GitHub Actions job with an agent CI skill

Write SKILL.md for fixing failing GitHub Actions workflows in this repository. The agent must diagnose before editing and must not weaken CI to get green.

Repository context:
[.github/workflows paths, default branch, package manager, how to run the same steps locally e.g. act, npm scripts]
Failing run context (paste when using the skill):
[workflow name, job id, link to run, error excerpt]

SKILL.md must include:
1. Purpose — restore CI truthfully; no silent skip of required jobs.
2. When to use / when not to use (include: stop if failure is flaky infrastructure — note rerun once, then escalate).
3. Hard rules:
   - Never paste secrets, tokens, or ${{ secrets.* }} values into chat or commits.
   - Never remove required jobs, delete fail-fast, or set continue-on-error on merge gates without explicit human approval noted in PR.
   - Prefer fixing the root cause (script, path, cache key, runner image) over pinning arbitrary old versions unless documented.
4. Required inputs: link to failed run, commit sha, and whether the failure started on main or only on a feature branch.
5. Steps:
   - Open the failed job log; quote the first actionable error line (not the whole log).
   - Map the failing step to local command: [list mapping table pattern e.g. "pnpm test" step → pnpm test locally].
   - Reproduce locally; if not reproducible, list environmental diffs (Node version, env vars by name only, cache).
   - Propose minimal diff; run the same local command again after the fix.
   - If workflow YAML changes, validate syntax and note which triggers still apply (pull_request, push, schedule).
   - Update PR description with: root cause, fix, and how you verified (command + exit code).
6. Two example prompts: unit test failure in CI vs cache/path drift in monorepo.
7. Pitfalls: commenting out steps, widening permissions without reason, bumping actions/@v tags without reading changelog, fixing only the symptom error while an earlier step still warns.
8. Done means: checklist — "failure reproduced or documented as env-only", "fix verified locally or re-run link attached", "no secret values in diff", "required checks still required."

Rules:
- Use real workflow file names from repo context; [confirm path] if unknown.
- Do not claim act or other tools work until you note [verify locally].
- Output only SKILL.md.