ci: add GitHub Actions workflow (Node 22, tsc check, vitest) on push/PR to main/staging

Author: Bubba

.github/workflows/ci.yml

@@ -0,0 +1,30 @@
+name: CI
+
+on:
+  push:
+    branches: [main, staging]
+  pull_request:
+    branches: [main, staging]
+
+jobs:
+  build:
+    name: Type-check & Test
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: '22'
+          cache: 'npm'
+
+      - name: Install dependencies
+        run: npm ci
+
+      - name: Type-check (tsc)
+        run: npm run check
+
+      - name: Run tests (vitest)
+        run: npm test