chore: enforce ruff format in pre-commit

Co-authored-by: Copilot App <[email protected]>

.pre-commit-config.yaml

@@ -13,6 +13,13 @@ repos:
         language: system
         types_or: [python, pyi]
         require_serial: true
+      - id: ruff-format
+        name: ruff format check
+        entry: uv run ruff format --check .
+        language: system
+        types_or: [python, pyi]
+        pass_filenames: false
+        require_serial: true
       - id: ty
         name: ty check (advisory)
         entry: python -c "import subprocess, sys; subprocess.run(['uv', 'run', 'ty', 'check']); sys.exit(0)"