Add auto formatting

.clang-format

@@ -0,0 +1,3 @@
+---
+BasedOnStyle: LLVM
+---

.github/workflows/format.yml

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+name: Format
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  format:
+    name: format
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: astral-sh/setup-uv@v6
+
+      - name: Check C++ formatting
+        run: uv run --group dev clang-format --dry-run --Werror include/hyperjet/*.h python/src/*.h python/src/*.cpp test/src/*.cpp benchmark/src/*.cpp
+
+      - name: Check Python formatting
+        run: uv run --group dev ruff format --check python/tests/