Validate Feature

Green unit tests prove that the assertions someone wrote pass. They do not prove the feature works. The gap between the two — an API that returns 201 where the client reads 200, a checkbox that flips in memory but never reaches the store, a form that clears on a failed submit — is where features ship broken. This skill closes it: drive the running system, not the test suite.

Run this after inspect-change, before land-branch.

1. Derive the acceptance checklist from the spec

Read the feature's requirements.md, design.md, and tasks.md. For every requirement describing user-observable behavior, list its concrete checks — the happy path AND each edge/error criterion — keyed to the requirement ID. The spec is the source: a behavior nobody hand-fed you is still on the hook, and an untraced one is a gap to raise, not to skip.