Move private runtime state outside checkouts and isolate worktrees

tests/test_standalone_smokes.py

@@ -29,11 +29,11 @@ SMOKES = [
 
 
 @pytest.mark.parametrize("filename", SMOKES)
-def test_standalone_smoke(filename):
+def test_standalone_smoke(filename, tmp_path):
     test_dir = pathlib.Path(__file__).resolve().parent
     result = subprocess.run(
         [sys.executable, str(test_dir / filename)],
-        cwd=test_dir.parent,
+        cwd=tmp_path,
         capture_output=True,
         text=True,
         timeout=90,