Test clang-format via Docker

.github/workflows/test-clang-docker.yml

@@ -0,0 +1,25 @@
+name: Test Clang Format Docker
+
+on:
+  push:
+    branches: [test-clang-format-install]
+  workflow_dispatch:
+
+jobs:
+  test-docker:
+    runs-on: ubuntu-24.04
+    steps:
+    - uses: actions/checkout@v3
+    
+    - name: Test clang-format via Docker
+      run: |
+        echo "=== Using silkeh/clang Docker image ==="
+        docker run --rm -v $PWD:/workspace silkeh/clang:18 clang-format --version
+        
+        echo ""
+        echo "=== Test formatting ==="
+        echo 'class Test { Test() {}; };' | docker run --rm -i silkeh/clang:18 clang-format
+        
+        echo ""
+        echo "=== Test with .clang-format ==="
+        echo 'class Test { Test() {}; };' | docker run --rm -i -v $PWD/formatters:/formatters silkeh/clang:18 clang-format --style=file:/formatters/.clang-format