update-feature

Update an existing feature's spec and design when requirements change. Use when the user wants to change, extend or fix the documented behavior of a feature, or has a new story for it. Finds the feature (or lets the user pick one, or create it if it does not exist), interviews the user, checks architecture patterns and 2nd/3rd-party API docs, edits spec.md and design.md in place, and records a changelog entry so implement-feature builds only what changed.