Add Prettier formatting check and build validation on pull requests to main

.github/workflows/build.yml

@@ -0,0 +1,25 @@
+name: Build
+
+on:
+  pull_request:
+    branches:
+      - main
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Set up Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: 22
+          cache: 'npm'
+
+      - name: Install dependencies
+        run: npm ci
+
+      - name: Run build
+        run: npm run build

.github/workflows/format.yml

@@ -0,0 +1,40 @@
+name: Format
+
+on:
+  pull_request:
+    branches:
+      - main
+
+jobs:
+  format:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: write
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+        with:
+          ref: ${{ github.head_ref }}
+          token: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Set up Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: 22
+          cache: 'npm'
+
+      - name: Install dependencies
+        run: npm ci
+
+      - name: Run Prettier
+        run: npm run format
+
+      - name: Run ESLint fix
+        run: npm run lint:fix
+
+      - name: Commit fixes if any
+        run: |
+          git config user.name "github-actions[bot]"
+          git config user.email "github-actions[bot]@users.noreply.github.com"
+          git diff --quiet && git diff --staged --quiet || (git add -A && git commit -m "style: auto-fix formatting and lint issues")
+          git push