ci: setup gated check-in

.github/workflows/gated-checkin.yml

@@ -0,0 +1,33 @@
+name: Gated Check-in
+
+on:
+  pull_request:
+    branches: [ "main" ]
+
+jobs:
+  build:
+    runs-on: macos-14
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4.1.1
+
+      - name: Setup Xcode Version
+        uses: maxim-lobanov/setup-xcode@v1.6.0
+        with:
+          xcode-version: latest-stable
+
+      - name: Install swift-format
+        run: |
+          brew update
+          brew install swift-format
+
+      - name: Lint using swift-format
+        run: |
+          /opt/homebrew/bin/swift-format lint -s -p -r ./
+
+      - name: Build and Analyze
+        run: >
+          xcodebuild clean build analyze
+          -project "Mochi Diffusion.xcodeproj"
+          -scheme "Mochi Diffusion"
+          CODE_SIGNING_ALLOWED=NO | xcpretty && exit ${PIPESTATUS[0]}