Implement

Build the work the user points you at — a PRD, or a set of issues.

• Drive /tdd wherever it fits, at the seams already agreed in the PRD.
• Typecheck often. Run individual test files often as you go, and the full suite once at the end — it should pass before you consider yourself done.
• When the build is complete, run /code-review over the diff and address what it surfaces.
• Commit your work to the current branch.