add format check, update prettier rules, apply rules consistently

.github/workflows/npm-format-check.yml

@@ -0,0 +1,23 @@
+name: NPM Format Check
+
+on: [push]
+
+jobs:
+  format-check:
+    runs-on: ubuntu-latest
+    timeout-minutes: 10
+
+    steps:
+      - name: "Checkout code"
+        uses: actions/checkout@v4
+
+      - name: "Use Node.js"
+        uses: actions/setup-node@v4
+        with:
+          node-version: '20.x'
+
+      - name: "Install npm dependencies"
+        run: npm ci
+
+      - name: "Check code formatting"
+        run: npm run format:check