ci: add GitHub Actions workflow for tests and Vercel deploy

Author: AlexVOiceover

.github/workflows/ci.yml

@@ -0,0 +1,53 @@
+name: CI
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: "20"
+          cache: "npm"
+
+      - name: Install dependencies
+        run: npm ci
+
+      - name: Run linter
+        run: npm run lint
+
+      - name: Run tests
+        run: npm test
+
+  deploy:
+    needs: test
+    runs-on: ubuntu-latest
+    if: github.event_name == 'push' && github.ref == 'refs/heads/main'
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: "20"
+          cache: "npm"
+
+      - name: Install Vercel CLI
+        run: npm install -g vercel
+
+      - name: Pull Vercel environment
+        run: vercel pull --yes --environment=production --token=${{ secrets.VERCEL_TOKEN }}
+
+      - name: Build project
+        run: vercel build --prod --token=${{ secrets.VERCEL_TOKEN }}
+
+      - name: Deploy to Vercel
+        run: vercel deploy --prebuilt --prod --token=${{ secrets.VERCEL_TOKEN }}