MinimumBoundingRectangle(Polygon) evaluated only the first (n + 1) / 2
edges, assuming opposite edges give the same rectangle. That holds only
for centrally symmetric hulls: for the triangle (0,0), (10,0), (12,1) it
returned area 12 instead of 10, depending on vertex order.
Every edge is now a candidate. A second-half edge replaces the best only
when smaller beyond rounding, so symmetric hulls (rectangles, best-fit
pairs, whose MBR angle PairEvaluator uses directly) keep their previous
orientation instead of flipping 180 degrees on floating-point noise.
On the Desktop problem nests, 8 of 160 drawing entries now get a smaller
MBR (0.004% to 3.2%) and a turned canonical frame; none changed without a
real area gain. The problem-nest corpus is unchanged against f51e5aef.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>