forked from 1b-agent/opencadstudio-upstream
Brings in the DWFFRAME/DGNFRAME header variables (codec #63) and robust 2D tangency plus ellipse-circle intersection (kernel #68). Pins opencadcodec ad16215, opencadkernel 1e02630, opencadgraph 7ef5ae4. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>