Add ConvexHull struct storing vertices with a support function that
returns the farthest point in a given direction, enabling GJK/EPA
collision detection. Update all Collider match arms across the physics
crate (collision, raycast, integrator, solver) to handle the new variant.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Add Capsule { radius, half_height } to the Collider enum, with AABB
computation and ray-vs-capsule intersection support. The capsule is
oriented along the Y axis (cylinder + two hemisphere caps).
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
