forked from 1b-agent/opencadstudio-upstream
Color converts as {'kind': ByLayer|None|ByBlock|Index|Rgb, 'value': ...}.
Leader.override_color is now writable; neither DWG nor DXF stores it, which
is recorded as a fourth persistence blocker with a canary assertion.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>