Add real YAML/CSV output examples generated from test fixtures,
document --bom/--bom-wiring flags, layout optimization, inspection
commands, and LTspice --ltspice-exe option.
- Use CalVer dot notation (2026.2.13) for PEP 440 compliance
- Filter pinlabels for top-level components when ground/power hidden
- Fix unused variables, long lines, import ordering (ruff clean)
- Use StrEnum for PinDirection (Python 3.11+)
- Add .gitignore and README.md
- All 105 tests pass including WireViz roundtrip validation