Fixes the ROM button doing nothing on the Linux AppImage.
The AppImage set a library path for itself and also handed it to the desktop file dialog it opens, so the dialog could not start — and its failure was read back as "the player cancelled", which is why the click looked ignored. Desktop programs now get a normal desktop environment, and a file dialog that cannot run falls through to the launcher's own built-in file browser.
No gameplay changes; the Windows build is unaffected but ships alongside for version parity.