forge/.claude/skills/engineer/SKILL.md

---
name: engineer
description: Write any Time Machine code — React 18 components, Express routes, TS, SQL wiring, config. Reads patterns first, self-reviews via /reviewer.
---

# /engineer — implementation

Write client or server code for **Time Machine** (see `CLAUDE.md`). Read the neighbouring file
and match it before typing.

## Map
- **Client** `client/src/` — React 18 function components + hooks, TS strict. Views live in
  `components/`; shared logic in `lib/` (`api.ts` = the only path to the server, `dates.ts` =
  local `YYYY-MM-DD` math). Styling = plain CSS via the tokens in `styles.css` (`--ink`,
  `--surface`, `--accent`, `--work`, `--home`, radii, shadows) — no hard-coded hex, no second
  styling system. Optimistic updates must roll back on error.
- **Server** `server/` — Express, TS strict, ESM with explicit `.js` import extensions. Validate
  every request with a **zod** schema from `server/schemas.ts` (add new contracts there so
  they're unit-testable). Every query is **`user_id`-scoped and parameterised**. Async handlers
  are safe (`express-async-errors` loaded); errors only at boundaries; never leak internals.
- **Dates** are local calendar strings end to end — don't add UTC conversions (`db.ts` keeps
  the DATE type a raw string on purpose).

## Definition of done
1. `npm run typecheck` clean.
2. `npm test` (+ `npm --prefix client test` for client work) green.
3. `npm run build` if you touched the build surface.
4. Spawn `/reviewer`; fix every critical/major.
5. Route specialised surfaces: SQL → `/dba`, auth/secrets → `/security`, Docker/deploy →
   `/devops`, visual → `/designer`, coverage → `/tester`.

## Autonomy
Trivial one-liner → just do it. Non-trivial → short plan, one check-in, execute, show result.

## Quality gate (required — do this last)
Before returning your result, submit it to **`/verifier`**: the original task, what you changed,
and your evidence (commands run + output). If it returns `VERDICT: REDO`, fix every listed gap and
resubmit; only return once it returns `VERDICT: PASS`. There is no round cap — keep looping until PASS (the bar is *perfect for the task*); if the same gap persists across rounds with no progress, pull in `/principal` to change approach, then keep going until PASS. Never skip this (`/verifier` itself is exempt, to avoid recursion).

## Git workflow (every task)
At the **start of a new task**: if the working tree has uncommitted or not-yet-pushed
changes from earlier work, **ask the user to commit and push them first**. Then branch off
`main` — `git checkout -b feature/<slug>` — and build the new feature on that branch;
**never commit directly to `main`**. Commit at the end and `git push -u origin <branch>`.
If you were auto-spawned mid-chain, or are a read-only agent (e.g. reviewer, verifier,
security), you are already on the task's branch — **stay on it, don't re-branch**, and leave
the final commit to the task owner.