fix(pytest): remove pytest section header and configure cache directory to dev/cache/

- Remove [pytest] section header from pytest.ini configuration file
- Add cache_dir setting to store pytest cache in dev/cache/.pytest_cache instead of project root
- Prevent .pytest_cache directory creation at root level

pytest.ini

@@ -1,4 +1,3 @@
-[pytest]
 # pytest configuration for AITBC
 
 # Test discovery
@@ -6,6 +5,9 @@ python_files = test_*.py *_test.py
 python_classes = Test*
 python_functions = test_*
 
+# Cache directory - prevent root level cache
+cache_dir = dev/cache/.pytest_cache
+
 # Custom markers
 markers =
     unit: Unit tests (fast, isolated)