Roslyn Bridge flagged these as copy-paste clusters; each pair now shares
one implementation so a fix lands everywhere at once:
- Shape.OffsetInward/OffsetOutward differed only in the target winding.
- BestFitFinder kept its own copy of SpatialQuery's arc-extreme points.
- SplitDrawingForm rebuilt DrawingSplitter's clip-region grid for preview.
- GeometryOptimizer's collinear/coradial finders (one misspelled
GetCoradialArs) become one generic FindRelated.
- Five settings files repeated the write-with-retry loop, and two also
repeated the unit parser and unreadable-file filter (SettingsFile).
- ClampsForm and SupportGridForm repeated their row/box builders.
- Vertical/HorizontalRemnantComparer share a RemnantComparer base.
Behavior is unchanged except that Engine/NestStorage settings loads now
also tolerate NotSupported/Security exceptions, matching the other
settings files' never-throw contract.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>