ToPolygon() used 1000 segments for every arc and circle regardless of
size: no more accurate for large arcs and needlessly dense for small
ones, which made every Drawing area and canonical-angle computation on
an arc-heavy part handle hundreds of thousands of vertices.
The parameterless overload now delegates to ToPolygonWithTolerance with
DefaultChordTolerance = 0.0001. That is ten times tighter than the
spacing and overlap checks' 0.001 because callers use this polygon for
area, which an inscribed polygon always under-reads: at 0.001, seven
area-sensitive cut-off, splitter and circle-packing tests drifted past
their precision; at 0.0001 all pass. ToPolygon(int) keeps the fixed
segment count for any caller that wants it.
With the one-pass Cleanup, a 300-nest PEP archive import on the forge
server went from 46.1 s to 15.5 s.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>