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>
Adds LayerType.Leadin to all LinearMove and ArcMove instances produced
by LineLeadIn, ArcLeadIn, LineArcLeadIn, CleanHoleLeadIn, and
LineLineLeadIn Generate() methods, plus tests covering all subclasses.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
