MuJoCo Warp 3.13.0 box collision patch

Original MuJoCo box collision algorithm:
Copyright 2016 Svetoslav Kolev
Source: google-deepmind/mujoco, tag 3.13.0, src/engine/engine_collision_box.c

Modified MuJoCo Warp files:
Copyright 2025 The Newton Developers
Source: google-deepmind/mujoco_warp, release 3.13.0

Both upstream projects are licensed under the Apache License, Version 2.0.
See LICENSE in this directory.

This patch ports CPU SAT, clipping, duplicate removal, and edge witnesses to
Warp with double-precision intermediates, and changes box-pair dispatch.
It preserves the tested patch from the SO101 physics report dated 2026-09-27.
The portable tests exercise the installed engine without runtime monkeypatches.
