ci: add typecheck/lint/test quality gate (#1)

* ci: add typecheck/lint/test quality gate (was deploying unguarded)

* ci: make quality gate functional — typecheck + test, drop unwired lint

The lint step ran `pnpm run lint` = `eslint .`, but eslint is not a dependency
of this repo (absent from pnpm-lock.yaml), so the step failed on command-not-found
and, since a failed step aborts the job, prevented typecheck from ever running —
a red, useless gate on every PR. Replace it with the vitest suite (`pnpm run test`,
88 passing) so the gate matches the PR's stated 'typecheck + test' intent and is
green on a clean tree. Typecheck now uses `pnpm run typecheck` (carries the
`-p tsconfig.json` the script defines). Wiring eslint is left as a separate decision.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>

.github/workflows/ci.yml

@@ -0,0 +1,42 @@
+name: CI
+
+# Quality gate: typecheck + test on every PR and non-main push.
+# 0pt previously relied solely on the Vercel build with no pre-merge gate.
+# Build is intentionally NOT run here because it needs runtime secrets
+# (POSTGRES_URL, ENGINE_URL, STRIPE, RESEND) — Vercel owns the build; CI owns
+# the static gate.
+#
+# Lint is intentionally NOT a step: this repo has no eslint dependency or
+# config wired (package.json's "lint" script is `eslint .`, but eslint is not
+# in the lockfile), so a lint step fails unconditionally on `command not found`
+# and — because a failed step aborts the job — would prevent typecheck/test
+# from ever running. Wiring eslint is a separate decision; until then the gate
+# is typecheck + the existing vitest suite, both of which pass on a clean tree.
+# Python engine (services/api) is gated separately if/when a Python workflow
+# is added.
+on:
+  pull_request:
+  push:
+    branches-ignore: [main]
+
+concurrency:
+  group: ci-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  gate:
+    name: Typecheck + test
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-node@v4
+        with:
+          node-version: '22'
+      - name: Enable corepack (pnpm)
+        run: corepack enable
+      - name: Install (frozen lockfile)
+        run: pnpm install --frozen-lockfile
+      - name: Typecheck (tsc --noEmit)
+        run: pnpm run typecheck
+      - name: Test (vitest)
+        run: pnpm run test