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

tests/Resources/test_audio_loader.cpp

@@ -0,0 +1,37 @@
+#include <gtest/gtest.h>
+#include <XCEngine/Resources/AudioLoader.h>
+#include <XCEngine/Resources/ResourceTypes.h>
+#include <XCEngine/Containers/Array.h>
+
+using namespace XCEngine::Resources;
+using namespace XCEngine::Containers;
+
+namespace {
+
+TEST(AudioLoader, GetResourceType) {
+    AudioLoader loader;
+    EXPECT_EQ(loader.GetResourceType(), ResourceType::AudioClip);
+}
+
+TEST(AudioLoader, GetSupportedExtensions) {
+    AudioLoader loader;
+    auto extensions = loader.GetSupportedExtensions();
+    EXPECT_GE(extensions.Size(), 1u);
+}
+
+TEST(AudioLoader, CanLoad) {
+    AudioLoader loader;
+    EXPECT_TRUE(loader.CanLoad("test.wav"));
+    EXPECT_TRUE(loader.CanLoad("test.mp3"));
+    EXPECT_TRUE(loader.CanLoad("test.ogg"));
+    EXPECT_FALSE(loader.CanLoad("test.txt"));
+    EXPECT_FALSE(loader.CanLoad("test.png"));
+}
+
+TEST(AudioLoader, LoadInvalidPath) {
+    AudioLoader loader;
+    LoadResult result = loader.Load("invalid/path/audio.wav");
+    EXPECT_FALSE(result);
+}
+
+} // namespace