test: create test to lint code

Author: russellwheatley

.github/workflows/swiftui-auth.yml

@@ -22,6 +22,25 @@ permissions:
   contents: read
 
 jobs:
+  format-check:
+    name: Swift Format Check
+    runs-on: macos-26
+    timeout-minutes: 10
+    steps:
+      - uses: actions/checkout@d632683dd7b4114ad314bca15554477dd762a938
+      
+      - name: Install swiftformat
+        run: brew install swiftformat
+        
+      - name: Check FirebaseSwiftUI formatting
+        run: swiftformat --lint ./FirebaseSwiftUI
+        
+      - name: Check SwiftUI Example formatting
+        run: swiftformat --lint ./samples/swiftui/FirebaseSwiftUIExample
+        
+      - name: Check Package.swift formatting
+        run: swiftformat --lint ./Package.swift
+
   # Package Unit Tests (standalone, no emulator needed)
   unit-tests:
     name: Package Unit Tests