Refactor code structure for improved readability and maintainability

tests/conftest.py

@@ -0,0 +1,12 @@
+from pathlib import Path
+
+import pytest
+
+
+def pytest_collection_modifyitems(items: list[pytest.Item]) -> None:
+    for item in items:
+        parts = Path(item.path).parts
+        if "unit" in parts:
+            item.add_marker(pytest.mark.unit)
+        elif "integration" in parts:
+            item.add_marker(pytest.mark.integration)