ci: add check-dist workflow

.github/workflows/check-dist.yml

@@ -0,0 +1,35 @@
+name: Check dist
+
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+    branches:
+      - main
+
+jobs:
+  check-dist:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v7
+
+      - name: Set up Node
+        uses: actions/setup-node@v7
+        with:
+          node-version-file: 'package.json'
+          cache: 'npm'
+
+      - name: Install dependencies
+        run: npm ci
+
+      - name: Build dist
+        run: npm run build
+
+      - name: Check for uncommitted changes
+        run: |
+          if [ -n "$(git status --porcelain dist/)" ]; then
+            echo "::error::dist/ is out of date. Run 'npm run build' and commit the result."
+            git diff dist/
+            exit 1
+          fi