test(Resources): Add comprehensive resource system tests (8 new test files, +48 test cases)

- Add Shader tests (8 test cases)
- Add Material tests (13 test cases)
- Add FileArchive tests (7 test cases)
- Add Loader tests for Texture, Mesh, Audio, Shader, Material (4 tests each)
- Implement IResourceLoader.cpp with ReadFileData and GetExtension
- Update CMakeLists.txt to include new test files and source

engine/CMakeLists.txt

@@ -176,6 +176,7 @@ add_library(XCEngine STATIC
     ${CMAKE_CURRENT_SOURCE_DIR}/src/Resources/ResourceCache.cpp
     ${CMAKE_CURRENT_SOURCE_DIR}/src/Resources/AsyncLoader.cpp
     ${CMAKE_CURRENT_SOURCE_DIR}/src/Resources/ResourceTypes.cpp
+    ${CMAKE_CURRENT_SOURCE_DIR}/src/Resources/IResourceLoader.cpp
     ${CMAKE_CURRENT_SOURCE_DIR}/src/Resources/Texture.cpp
     ${CMAKE_CURRENT_SOURCE_DIR}/src/Resources/Mesh.cpp
     ${CMAKE_CURRENT_SOURCE_DIR}/src/Resources/TextureLoader.cpp

engine/src/Resources/IResourceLoader.cpp

@@ -0,0 +1,42 @@
+#include "XCEngine/Resources/IResourceLoader.h"
+#include <fstream>
+
+namespace XCEngine {
+namespace Resources {
+
+Containers::Array<Core::uint8> IResourceLoader::ReadFileData(const Containers::String& path) {
+    Containers::Array<Core::uint8> data;
+    
+    std::ifstream file(path.CStr(), std::ios::binary | std::ios::ate);
+    if (!file.is_open()) {
+        return data;
+    }
+    
+    std::streamsize size = file.tellg();
+    file.seekg(0, std::ios::beg);
+    
+    data.Resize(static_cast<size_t>(size));
+    if (!file.read(reinterpret_cast<char*>(data.Data()), size)) {
+        data.Clear();
+    }
+    
+    return data;
+}
+
+Containers::String IResourceLoader::GetExtension(const Containers::String& path) {
+    Containers::String ext;
+    size_t dotPos = Containers::String::npos;
+    for (size_t i = path.Length(); i > 0; --i) {
+        if (path[i - 1] == '.') {
+            dotPos = i - 1;
+            break;
+        }
+    }
+    if (dotPos != Containers::String::npos) {
+        ext = path.Substring(dotPos + 1);
+    }
+    return ext;
+}
+
+} // namespace Resources
+} // namespace XCEngine