Address code review: fix busy-wait, add file-open error handling

Agent-Logs-Url: https://github.com/starbounded-dev/LuxEngine/sessions/a7b976e8-d569-4fb6-889e-44131bcfcc6a

Co-authored-by: sheazywi <73042839+sheazywi@users.noreply.github.com>

Author: Copilot

Core/Source/Lux/Asset/MaterialSerializer.cpp

@@ -42,6 +42,11 @@ namespace Lux
 		out << YAML::EndMap;
 
 		std::ofstream fout(filepath);
+		if (!fout.is_open())
+		{
+			LUX_CORE_ERROR("MaterialSerializer: Could not open '{}' for writing", filepath.string());
+			return;
+		}
 		fout << out.c_str();
 	}
 

Core/Source/Lux/Asset/MeshSerializer.cpp

@@ -56,6 +56,11 @@ namespace Lux
 		out << YAML::EndMap;
 
 		std::ofstream fout(filepath);
+		if (!fout.is_open())
+		{
+			LUX_CORE_ERROR("MeshSerializer: Could not open '{}' for writing", filepath.string());
+			return;
+		}
 		fout << out.c_str();
 	}
 
@@ -119,6 +124,11 @@ namespace Lux
 		out << YAML::EndMap;
 
 		std::ofstream fout(filepath);
+		if (!fout.is_open())
+		{
+			LUX_CORE_ERROR("StaticMeshSerializer: Could not open '{}' for writing", filepath.string());
+			return;
+		}
 		fout << out.c_str();
 	}
 

Core/Source/Lux/Asset/RuntimeAssetManager.cpp

@@ -23,7 +23,8 @@ namespace Lux {
 		// runtime because assets are expected to be pre-loaded asynchronously.
 		LUX_CORE_WARN("RuntimeAssetManager::GetAsset – synchronous load for handle {}", (uint64_t)handle);
 
-		// Trigger an async load and wait for it (simple spin).
+		// Trigger an async load and sleep briefly between sync polls to avoid
+		// burning CPU cycles while waiting for the worker thread.
 		std::atomic_bool done{ false };
 		LoadAssetAsync(handle, [&done](AssetHandle, Ref<Asset>)
 		{
@@ -33,7 +34,8 @@ namespace Lux {
 		while (!done)
 		{
 			SyncLoadedAssets();
-			std::this_thread::yield();
+			using namespace std::chrono_literals;
+			std::this_thread::sleep_for(1ms);
 		}
 
 		return IsAssetLoaded(handle) ? m_LoadedAssets.at(handle) : nullptr;