0e961ba4b1
Reworks multiple shaders and materials for URP compatibility and adds a Loading screen/scene and a few model imports. Key changes: - Converted ProBuilder standard vertex-color shader and several particle/surface shaders to URP HLSL passes (UniversalForward, ShadowCaster, Depth, DepthNormals) preserving base texture * tint * vertex color, normal map and PBR parameters. - Updated particle SurfaceShader_VC to a URP forward pass and simplified lighting to use URP shader library helpers. - Updated materials (landMark, tile) to point to project textures, adjust keywords/flags (e.g. XRMotionVectorsPass, disable ShadowCaster for one), tweak tiling and base color values. - Added a Loading screen UI (UXML, USS) and LoadingScreenController.cs plus a new Loading scene and scene metadata. - Imported new FBX assets (T-Pose, Untitled) and updated Editor build settings / project settings to include the new Loading scene. These changes migrate rendering code to the Universal Render Pipeline and add a basic loading UI/scene, while updating materials and project settings accordingly.