fill_contains promised to close open subpaths (as their fill does) but
counted kurbo's winding, which leaves the closing edge out: a point beside
it read as outside. An open path (an anchor deleted from a closed one) lost
its fill clicks on that side, and a reflection moved the edge across, so it
looked like Reflect broke selection. Open subpaths are now closed by a
straight line back to their start before the winding is counted; closed
paths are borrowed as they are.
Tests: the open path from the report, on both sides and even-odd; reflected
shapes, imported SVG hearts, a selected shape dragged by its fill.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>