refactor: improve test infrastructure and fix OpenGL GLAD initialization

- Rename D3D12Enum.h to D3D12Enums.h for naming consistency
- Fix OpenGL unit test GLAD initialization by using gladLoadGL()
  instead of gladLoadGLLoader(wglGetProcAddress) for fallback support
- Migrate remaining tests to use gtest_discover_tests for granular
  test discovery (math, core, containers, memory, threading, debug,
  components, scene, resources, input, opengl)
- Remove obsolete TEST_RESOURCES_DIR and copy_directory commands
  from OpenGL unit test CMakeLists (minimal/Res doesn't exist)
- Update TEST_SPEC.md with performance metrics and per-module
  build/test commands for faster development workflow
- Update CMake path references to use lowercase paths

engine/src/RHI/D3D12/D3D12Device.cpp

@@ -217,7 +217,9 @@ RHIBuffer* D3D12Device::CreateBuffer(const BufferDesc& desc) {
 RHITexture* D3D12Device::CreateTexture(const TextureDesc& desc) {
     auto* texture = new D3D12Texture();
     D3D12_RESOURCE_DESC d3d12Desc = {};
-    d3d12Desc.Dimension = static_cast<D3D12_RESOURCE_DIMENSION>(desc.textureType);
+    
+    d3d12Desc.Dimension = ToD3D12(static_cast<TextureType>(desc.textureType));
+    
     d3d12Desc.Width = desc.width;
     d3d12Desc.Height = desc.height;
     d3d12Desc.DepthOrArraySize = desc.depth;