Add automatic pytest sys.path configuration in tests/conftest.py and clean up
unused imports in application files.
SESSION_EXECUTION_AUTHORIZATION recorded from user request.
tests/conftest.py.ruff check src/ tests/ --fix to clean unused imports.PYTHONPATH.tests/conftest.py with automatic src/ insertion into sys.path.src/data2dsl_cli.py, src/data2dsl_skill.py, tests/test_golden_case_e2e.py.