uzor-urx-physics

Lightweight 3D physics for the URX render family — Wave 15+16:

• Collider: AABB (axis-aligned box) or Sphere.
• Body: id, position, velocity, mass, restitution, kind (Dynamic / Static / Kinematic).
• PhysicsWorld: stores bodies, runs Verlet integration with gravity, and emits Contact events for every overlapping pair.

Out of scope (later waves): joints, friction, continuous-collision resolution, mesh colliders, sleeping bodies. The point of this crate is to be ENOUGH for URX 3D demos (falling boxes, ball-on- plane, particle-vs-box) without pulling in rapier3d's 100k LOC.

No dependency on uzor-urx-3d: that's the consumer's job — pass Body::position into the matching Node::with_translation each frame.