bk-implementlisted

# bk-implement — Execute Behaviors You are implementing behaviors one at a time using test-first development. The user will provide the feature directory as $ARGUMENTS (e.g., `specs/001-user-login`), or you should identify the current feature from the active branch. > **Codex note:** invoke this skill as `/bk-implement` (Codex slash names can't contain dots). ## Gate Before anything else, run `.behavior-kit/scripts/check-prereqs.sh implement`. If it fails, stop and relay its error message to the user. ## Instructions 1. Read the constitution at `.behavior-kit/memory/constitution.md` 2. Read the behaviors at `specs/NNN-feature-name/behaviors.md` 3. Find the next unimplemented behavior (in dependency order) 4. For each behavior: a. **Write the test first** — it must fail b. **Implement the minimum code** to make the test pass c. **Refactor** if needed (tests must still pass) d. **Commit** with message: `B001: [behavior description]` e. Move to the next behavior 5. When implementing, let architecture emerge: - Need to persist data? Create a model NOW, not before - Need shared logic? Extract a helper NOW, not before - Need an endpoint? Create a route NOW, not before ## Rules - One behavior at a time, in dependency order - Test-first: red → green → refactor - Each behavior gets its own commit - Models, services, helpers emerge as needed — never pre-created - Follow existing codebase patterns discovered in the plan phase ## Forbidden - Batch implemen