Priority-based snapping: when the cursor is within 10px of an entity
endpoint or midpoint, snaps to it instead of the nearest contour point.
Diamond marker (endpoint) or triangle marker (midpoint) replaces the
lime dot to indicate active snap. Also refactors OnPaint into focused
helper methods and adds Arc.MidPoint().
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Remove LeadInsLocked guard so parts can be re-selected for lead-in
re-placement. Change preview color from yellow to magenta for better
visibility against the cyan contour highlight.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Scribe/etch lines were being treated as cut contours by
ContourCuttingStrategy, receiving lead-ins and kerf compensation.
Now they are separated before ShapeProfile construction and emitted
as plain moves with LayerType.Scribe preserved.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Scales down lead-ins that would place the pierce point too close to the
opposite wall of small holes. Uses quadratic solve to find the maximum
safe distance inside a clearance-reduced radius. Adds Scale() method to
all LeadIn types and applies clamping in both the strategy and the
interactive preview.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
