Set reuseExistingServer:true in playwright config so acceptance gates
don't fail when port 41700 is already occupied by a prior test run.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Add workflow engine with acceptance gates, test recording, and review
queue. Frontend displays gate status (blocked/ready), test summaries,
failing badges, and warnings. Proceed action is disabled when gates
are not met. Includes 13 unit tests (Vitest) and 9 E2E tests
(Playwright) covering all five acceptance criteria.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>