refactor: route builtin forward pipeline through shader assets

engine/src/Resources/Shader/ShaderLoader.cpp

@@ -1,4 +1,5 @@
 #include <XCEngine/Resources/Shader/ShaderLoader.h>
+#include <XCEngine/Resources/BuiltinResources.h>
 #include <XCEngine/Core/Asset/ResourceManager.h>
 #include <XCEngine/Core/Asset/ResourceTypes.h>
 
@@ -22,12 +23,20 @@ Containers::Array<Containers::String> ShaderLoader::GetSupportedExtensions() con
 }
 
 bool ShaderLoader::CanLoad(const Containers::String& path) const {
+    if (IsBuiltinShaderPath(path)) {
+        return true;
+    }
+
     Containers::String ext = GetExtension(path);
     return ext == "vert" || ext == "frag" || ext == "geom" || 
            ext == "comp" || ext == "glsl" || ext == "hlsl" || ext == "shader";
 }
 
 LoadResult ShaderLoader::Load(const Containers::String& path, const ImportSettings* settings) {
+    if (IsBuiltinShaderPath(path)) {
+        return CreateBuiltinShaderResource(path);
+    }
+
     Containers::Array<Core::uint8> data = ReadFileData(path);
     if (data.Empty()) {
         return LoadResult("Failed to read shader file: " + path);