guimaraf/3sxw — reverse-engineered prompt

Build me a portable modern PC version of the 3SX Street Fighter III 3rd Strike project, based on the existing reverse engineered PS2 port idea. Keep it legal, don’t include any original game assets, and make it expect the player to provide their own official copy.

I want the game folder to be fully self contained. Saves, replays, settings, key mappings, assets, and debug logs should all stay inside the same folder as the executable so I can copy it to another computer and it still works.

Please make saving and loading reliable, with no weird missing files or corrupted progress. On a fresh save, Gill should already be available like a normal unlocked character, but keep him out of online play. Extra Options should still unlock the normal way after clearing Arcade Mode with Gill and saving.

Also add a runtime debug mode that writes useful performance and input logs for troubleshooting stutter. Make it buildable on Windows, Linux, and macOS, and look up current docs online if you need to.