What problem does it solve? It enforces a disciplined ticket implementation workflow where acceptance criteria become failing behavior tests before any code is written, preventing untested changes and post-hoc test tampering. ## Core Features & Use Cases - Acceptance-Test-First: Converts each ticket acceptance criterion into a behavior test at the seam defined by the project's test strategy, then verifies it fails for the right reason. - Test Locking: Commits acceptance tests in an isolated commit that becomes read-only, with a diff check at the end to detect any modification of the locked tests. - Exception Handling: Skips the red-green cycle for pure refactors and uses evidence-based verification for non-automatable criteria like visuals or interactions. - Use Case: You claim a ticket changing login behavior. Write the new acceptance tests, watch them fail, lock them in a dedicated commit, implement the full slice freely, then prove the tests pass and the locked tests are untouched. ## Quick Start Use the implement skill to work on ticket 42, writing acceptance tests first and locking them before implementing the change.