feat(physics): Implement SDF-based physics engine and BVH

Completed Task #49.
- Implemented CPU-side SDF library (sphere, box, torus, plane).
- Implemented Dynamic BVH construction (rebuilt every frame).
- Implemented PhysicsSystem with semi-implicit Euler integration and collision resolution.
- Added visual debugging for BVH nodes.
- Created test_3d_physics interactive test and test_physics unit tests.
- Updated project docs and triaged new tasks.

1 files changed, 2 insertions, 0 deletions

diff --git a/src/3d/visual_debug.h b/src/3d/visual_debug.h
index 456cb10..6173fc4 100644
--- a/src/3d/visual_debug.h
+++ b/src/3d/visual_debug.h
@@ -25,6 +25,8 @@ class VisualDebug {
   void add_box(const mat4& transform, const vec3& local_extent,
                const vec3& color);
 
+  void add_aabb(const vec3& min, const vec3& max, const vec3& color);
+
   // Render all queued primitives and clear the queue
   void render(WGPURenderPassEncoder pass, const mat4& view_proj);