Allow negative scroll factor to invert natural scroll for select applications (?)

[Sharps1ght]

Coming from Hyprland I found Niri doesn't allow for natural scrolling per-application due to libinput handling all of the inputs, but Niri allows per-application scroll factors and does not allow negative values. It would still be sort of a workaround, but a working one? Will be really cool to have that.

[YaLTeR]

Per-app natural scrolling should be possible but it's different than just negative scroll factor bc the compositor communicates the scroll direction to the client