Support Second controller port (or not if disabled) and have a fancy background

examples/PoolBox/application/include/shared.hpp

@@ -1,6 +1,9 @@
 #pragma once
 #include "../src/include/menu.hpp"
+#include "../src/include/font_writer.hpp"
+#include <PSX/GPU/gpu_types.hpp>
 
 namespace Shared {
-    extern Menu::BackMenu back_menu;
+    extern Menu::BackMenu           back_menu;
+    extern JabyEngine::GPU::POLY_G4 background;
 }