Add GitHub actions CI checks

.github/workflows/ci.yml

@@ -0,0 +1,20 @@
+name: CI
+on: [push]
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        node: [18, 20, 22]
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-node@v4
+        with:
+          node-version: ${{ matrix.node }}
+          cache: 'npm'
+      - run: npm ci
+      - run: npm run format:check
+      - run: npm run build
+      - run: npm test
+      - run: npm run lint
+      - run: npm run compile-schemas && git diff --exit-code