The render-alpha clamp test compared physics vs render position with
xunit precision:4 (Math.Round semantics); the AP-7 friction port shifts
the velocity-fallback trajectory by 7.6 um, landing two essentially
equal values on opposite sides of a 5e-5 rounding boundary. Assert with
a 1 mm tolerance instead. Merged-tree full Release suite: 9,887 passed /
0 failed / 5 skips including Headless (the exposed velocity-fallback
path holds).
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>