I completely misunderstood the RFD doc comments,
thought that save file dialogs were not avaliable on linux outside of gtk
this helps avoid the wrapper, which is nice;
but I imagine it would fail if portals are unavaliable.
this makes the logic drastically simpler;
as it comes with image crate integration.
however, images can no longer be saved as JXL with this version
(as jxl-oxide is decoder-only)
