- Add Material component with Albedo, Roughness, Metallic.
- MeshRenderer reads Material and tints vertex color; falls back to default.
- Add Blinn-Phong specular using camera position pushed via push constants.
- Add floor plane and grid mesh in Program.cs.
- Add OrbitCameraController with right-mouse orbit and mouse-wheel zoom.
- Forward SDL events to InputMapping from Sdl3Window.PumpEvents.
- Update main loop to update camera and aspect ratio on resize.
- Recompile SPIR-V shaders.
- Update CORTEX_ENGINE_ARCHITECTURE.md with Material, lighting, and orbit camera.