ci: add build and audit gate

.github/workflows/ci.yml

@@ -0,0 +1,24 @@
+name: CI
+
+on:
+  pull_request:
+    branches: [main]
+  push:
+    branches: [main]
+  workflow_dispatch:
+
+jobs:
+  build-and-audit:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-node@v4
+        with:
+          node-version: 20
+          cache: npm
+      - name: Install dependencies
+        run: npm ci
+      - name: Build
+        run: npm run build
+      - name: Audit high and critical vulnerabilities
+        run: npm audit --audit-level=high