Add CI: oxlint, oxfmt, Playwright E2E + GitHub Actions

.github/workflows/ci.yml

@@ -0,0 +1,51 @@
+name: CI
+
+# Runs on pull requests only. `main` is protected so code only lands via PRs,
+# which this validates before merge; Vercel handles build & deploy on push.
+on:
+  pull_request:
+    branches: [main]
+
+# Cancel superseded runs on the same PR (e.g. rapid pushes to a branch).
+concurrency:
+  group: ci-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  ci:
+    name: ci
+    runs-on: ubuntu-latest
+    timeout-minutes: 15
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-node@v4
+        with:
+          node-version: 24
+          cache: npm
+
+      - name: Install dependencies
+        run: npm ci
+
+      - name: Lint (oxlint)
+        run: npm run lint
+
+      - name: Format check (oxfmt)
+        run: npm run format:check
+
+      - name: Build
+        run: npm run build
+
+      - name: Install Playwright browser
+        run: npx playwright install --with-deps chromium
+
+      - name: E2E tests (Playwright)
+        run: npm test
+
+      - name: Upload Playwright report
+        if: ${{ !cancelled() }}
+        uses: actions/upload-artifact@v4
+        with:
+          name: playwright-report
+          path: playwright-report/
+          retention-days: 7

.gitignore

@@ -18,6 +18,13 @@ skills-lock.json
 # debug screenshots from spike scripts
 spike/*.png
 
+# playwright e2e artifacts
+test-results/
+playwright-report/
+blob-report/
+playwright/.cache/
+.last-run.json
+
 # os
 .DS_Store
 .vercel

.oxfmtrc.json

@@ -0,0 +1,4 @@
+{
+  "$schema": "./node_modules/oxfmt/configuration_schema.json",
+  "ignorePatterns": ["dist", ".vercel", ".astro", "node_modules", "spike", "package-lock.json"]
+}

.oxlintrc.json

@@ -0,0 +1,8 @@
+{
+  "$schema": "./node_modules/oxlint/configuration_schema.json",
+  "categories": {
+    "correctness": "error",
+    "suspicious": "warn"
+  },
+  "ignorePatterns": ["dist", ".vercel", ".astro", "node_modules", "spike"]
+}

CONTRIBUTING.md

@@ -42,11 +42,18 @@ map. In short:
 2. Create a branch off `main`: `git checkout -b my-feature`.
 3. Keep changes focused — one logical change per pull request.
 4. Match the existing style: TypeScript, Astro components, and the current
-   formatting/naming conventions. No formatter config is enforced yet, so just
-   keep diffs clean and consistent with surrounding code.
-5. **Test your change manually**: run `npm run dev` and exercise both demo mode
-   and (if you have Plus) real mode. Run `npm run build` to confirm the
-   production build passes.
+   conventions. Linting and formatting are enforced in CI:
+   - `npm run lint` — [oxlint](https://oxc.rs) (fast Rust linter)
+   - `npm run format` — [oxfmt](https://oxc.rs/docs/guide/usage/formatter.html)
+     to auto-format, or `npm run format:check` to verify
+     (oxfmt is still alpha and does not format `.astro` files yet, so keep those
+     tidy by hand.)
+5. **Test your change**: `npm test` runs the Playwright E2E suite against the
+   demo flow. Also exercise it manually with `npm run dev` (and real mode if you
+   have Plus), and run `npm run build` to confirm the production build passes.
+
+All of the above (`lint`, `format:check`, `build`, `test`) run automatically on
+every pull request via GitHub Actions, and must pass before a PR can be merged.
 
 ## Security