add format workflow

.github/workflows/format.yml

@@ -0,0 +1,31 @@
+name: 'Format Check'
+
+on:
+
+  workflow_dispatch:
+
+  push:
+    branches:
+      - main
+
+  pull_request:
+
+permissions:
+  contents: read
+  pull-requests: read
+
+concurrency:
+  group: '${{ github.workflow }} @ ${{ github.event.pull_request.head.label || github.head_ref || github.ref }}'
+  cancel-in-progress: true
+
+jobs:
+  check-format:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout & Setup Toolchain
+        uses: actions/checkout@v4
+        uses: actions-rust-lang/setup-rust-toolchain@v1
+
+      - name: Run Formatter
+        run: cargo fmt --check
+