warn if prototype file does not exist

fggl/ecs3/prototype/loader.cpp

@@ -18,6 +18,10 @@ namespace fggl::ecs3 {
 
 	void load_prototype_file( ecs3::World& world, data::Storage& storage, const std::string& name ) {
 		auto path = storage.resolvePath( data::Data, name );
+		if ( !std::filesystem::exists(path) ) {
+			debug::log(debug::Level::warning, "prototype file not found: {}", path.string());
+			return;
+		}
 
 		auto root = YAML::LoadFile( path.string().c_str() );
 		for (const auto& node : root["prefabs"] ) {