Implement

Builds exactly one ticket per session by default. Read CONTEXT.md's "## Engineering Setup" section for the tracker/repo. See the tdd skill for the full red-green-refactor discipline this relies on.

Steps

1. Claim the ticket. If using GitHub/GitLab, assign it to yourself (gh issue edit <n> --add-assignee @me) before starting — this is what tells anyone else it's taken. Read the linked spec section for full context, not just the ticket body.

2. Branch. Create ticket/<n>-<short-slug> off the base branch.

3. Red-green-refactor loop (see tdd for detail): write a failing test for the smallest next piece of the ticket's acceptance criteria, make it pass, refactor, repeat until every acceptance criterion this ticket covers is met.