What problem does it solve? It closes the gap between a product definition and its implementation by verifying every acceptance criterion of in-scope user stories, confirming bug fixes against their original reproduction, and guaranteeing durable e2e and regression test coverage before a change is marked done. ## Core Features & Use Cases - Acceptance Criteria Verification: Checks each criterion of every in-scope story individually in the running app or via the test suite, never marking criteria as assumed passing. - Bug Regression Testing: Repeats the original bug reproduction to confirm the fix, then creates or updates a regression test that would have caught the bug. - E2E Coverage Management: Creates or updates end-to-end tests per story following existing test patterns and the configured e2eDir, running them until green. - Use Case: After implementing a feature change, invoke this stage to walk through each story's acceptance criteria in the running app, add missing e2e tests, and stamp the test stage complete via the DefProd MCP server. ## Quick Start Ask the agent to run the test stage for the current change and verify all acceptance criteria of the in-scope stories.