buildlisted

# build — TDD vertical slices Implement work the way a senior engineer does: smallest valuable slice first, test-first, frequent commits, following the repo's existing patterns. ## Steps 1. **Read the Spine.** Load `conventions.md` (commands + patterns to follow), `context.md` (architecture + language), and the acceptance criteria in `journal.md`. If there are no criteria yet, run `align` first. 2. **Pick the smallest vertical slice** that delivers one acceptance criterion end to end. 3. **Red:** write a failing test that pins the desired behavior. Run it; confirm it fails for the *expected* reason. 4. **Green:** write the minimal code to pass. Run the test; confirm it passes. 5. **Refactor:** improve names and structure with tests green. Favor deep modules with simple interfaces — avoid balls of mud. 6. **Commit** the slice with a clear message. 7. **Update the Spine.** In `journal.md`, tick the criterion, set the next step. 8. Repeat until all criteria are met. Stop and report if a criterion is blocked. ## Spine I/O - **Reads:** `conventions.md`, `context.md`, `journal.md`. - **Writes:** `journal.md` (progress, next step). ## Notes - Use the test/typecheck commands from `conventions.md`, not invented ones. - Name code using the Spine's shared language for consistency. - Don't claim a slice is done without running its test — that's `verify`'s rule too, applied continuously here.