The full-ring annulus built the inner ring as a separate QPainterPath and
merged it with addPath, which stitched a spurious segment from (0,0) to
the ring. Build both concentric rings as subpaths of one path, each begun
with an explicit moveTo, so there is no connecting segment.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>