forked from 1b-agent/opencadstudio-upstream
A custom entity without its object enabler (an AutoCAD Architecture door,
wall, ...) arrives as Unknown but ships a cached proxy-graphics preview —
the vector fallback AutoCAD itself draws. The old decoder read only a lone
type-6 polyline; generalise it to the real record stream
([total_size, record_count, {record_size, record_type, data}...]) and decode
the geometry records: polyline (6), polygon (7, closed) and circular arc
(4/5, flattened to a strip). Trait records (colour/lineweight/...) are
skipped for now, so the preview draws in the entity's own colour.
The Unknown-entity path now draws every decoded primitive in one wire, so
these objects appear (and become selectable) instead of vanishing.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>