- Add python/tests/conftest.py with MagicMock stubs for pcbnew/skip
- Add python/tests/test_schematic_tools.py with 29 tests covering
WireManager.delete_wire, WireManager.delete_label (unit + integration),
and parameter validation for all 11 new _handle_* methods
- Apply black formatting to component_schematic.py, wire_manager.py,
and kicad_interface.py
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
