Replace polygon boolean clipping with direct entity splitting using
bounding box filtering and exact intersection math. Eliminates Clipper2
precision drift that caused contour gaps (0.0035") breaking area
calculation and ShapeBuilder chaining.
Also fixes SpikeGrooveSplit: spike depth is now grooveDepth + weldGap
(spike protrudes past groove), both V-shapes use same angle formula,
and weldGap no longer double-subtracted from tip depth.
SplitDrawingForm: fix parameter mapping (GrooveDepth direct from nud,
not inflated), remove redundant Spike Depth display, add feature
contour preview and trimmed split lines at feature positions.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
AJ Isaacs
39f8a79cfd