Rounding standing-plane coefficients to four decimals moved the Mid slope
inside its own collider, so capsule clearance rejected the whole surface and
players there fell back to the ground level. Keep ten decimals when grouping
coplanar faces, compile the measured slope back into both Pearl models, and
pin it with a test that checks the standing floor and its open view.

Codex did this work; Dara ran it. Assets rebuilt from the pre-anomaly
baseline so this commit carries only the Pearl supports.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>