[HenryCordes]

Summary

The README claimed implementation "often" uses parallel subagents, with nothing in the repo backing that up beyond one sequential test-writer agent. This adds a real artifact for that claim, plus an honest retrospective on the workflow's first PR.

Changes

• .claude/workflows/parallel-review.js — a runnable multi-agent workflow: three reviewers (correctness, security, this project's own standards in AGENTS.md/docs/REACT_GUIDELINES.md) run in parallel against git diff <base>...HEAD, and every finding then goes through an independent skeptic agent before being reported. Verified the harness discovers and parses it correctly — it shows up as an available workflow after the file was added.
• docs/CASE_STUDY.md — a retrospective on PR Harden showcase tooling and add a second worked example #1, written to keep the real friction rather than a sanitized success story: a fake-timer test race (Promise.all racing the timer advance against the promise, instead of sequencing them) and a toMatchObject that silently ignored a non-enumerable Error.cause property.
• eslint.config.js — scoped .claude/workflows out of the app's lint config, same precedent as .husky (these are harness-context scripts, not application source).
• README — links the case study from "The workflow," documents the new workflow script under "Context engineering," and adds both to the repo tour.

Testing

• pnpm lint && pnpm typecheck && pnpm format:check && pnpm test — all green (21 tests, unchanged by this PR).
• Validated parallel-review.js's syntax against the harness's actual execution model (the export const meta literal parses standalone; the rest of the body parses when wrapped in an async function, matching how the Workflow tool documents executing script bodies) — plain node --check isn't valid here since top-level await/return are only legal inside that wrapper.
• Did not actually execute the workflow (that requires explicit multi-agent-orchestration opt-in, which wasn't part of this request) — only verified it's well-formed and discoverable.

Related

PROJ-000 (placeholder — no issue tracker on this personal showcase repo).

Checklist

• pnpm lint:fix && pnpm typecheck && pnpm test pass locally
• Tests added/updated for the change — N/A, no testable application code changed (workflow script + docs only)
• N/A — no UI change
• Branch name follows {username}/{TICKET}-{description}