jawaidbazyar2/gssquared ? reverse-engineered prompt

Build me a polished desktop app for running classic Apple II software, especially the Apple IIgs, but also the earlier Apple ][, ][+, and //e models. I want it to feel like a complete ready to use emulator, with a simple interface, sound, graphics, keyboard, mouse, and disk image support, and it should work on Windows, Linux, and macOS.

Please make it easy to launch games and demos, load and swap disks, and keep the experience friendly for someone who just wants to run old Apple software without extra setup. If needed, look up the current docs online and make sure the build and packaging flow works cleanly on modern machines. Also include the extra helper tools for disk image inspection and conversion if they fit naturally. Use C++ and keep it cross platform, with SDL handling the display, audio, and input.