FilterPanel.LoadItem was hardcoding all layer and line type checkboxes
to checked, ignoring actual visibility state. Now reads Layer.IsVisible
and entity IsVisible to set correct checked state.
Also guard DetermineWinding against shapes with fewer than 3 polygon
points (defaults to CCW) to prevent crash when applying lead-ins.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
AJ Isaacs
ba89967448