- Fix conftest.py: use subprocess for init, remove unused cli_env fixture
- Update all test files to use data_dir parameter instead of env
- Remove mock-based TestJSONLOutput class from tests_piping.py
- Remove unused imports (MagicMock, patch)
- Fix file permissions for cli_utils.py
All tests now use real subprocess calls per CLAUDE.md guidelines:
- NO MOCKS - tests exercise real code paths
- NO SKIPS - every test runs