The find_model response now returns plane_polygon_px (4 corners of a 30 cm square anchored at the work plane centroid, projected to RGB pixels via the same K used for the SAM21 cloud). The GUI gains a 'Piano (viola)' checkbox that draws the polygon as a translucent violet quad with an outline, helping the operator see whether the plane sits where expected relative to the object. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>