Refactor event handling in Controller::OnInput to use SDL_WaitEvent instead of polling; improves efficiency by reducing CPU usage during event processing.

src/app/core/controller.cc

@@ -64,7 +64,7 @@ void Controller::OnInput() {
   ImGuiIO &io = ImGui::GetIO();
   SDL_Event event;
 
-  while (SDL_PollEvent(&event)) {
+  SDL_WaitEvent(&event);
   ImGui_ImplSDL2_ProcessEvent(&event);
   switch (event.type) {
     case SDL_KEYDOWN:
@@ -91,7 +91,6 @@ void Controller::OnInput() {
     default:
       break;
   }
-  }
 
   int mouseX;
   int mouseY;