add a close button to the main toolbar when running on gamescope

[leia-uwu]

i don't own a steam deck to test this, but it worked on a local gamescope session so ig it will also work on the steam deck

closes #522

[leia-uwu]

(forgot to sign the commit lol)

[Scrumplex]

I wonder if there is a more general solution. Perhaps we can somehow query if server-side decorations are present and add this action depending on that?

[leia-uwu]

I wonder if there is a more general solution. Perhaps we can somehow query if server-side decorations are present and add this action depending on that?

hmm, gamescope only supports xwayland clients so idk :ioa:
when running natively on wayland qt adds client side decorations if theres no server side ones

[leia-uwu]

i totally didn't do this pr while sleep deprived and wrote instance toolbar instead of main toolbar lmao

[Ryex]

It actualy would be nice to detect the case of no window decorations to add the close button. I use tileing windows managers like bspwm without decorations from time to time, that would be a nice to have.

[Scrumplex]

Maybe just add a FIXME comment to make this more universal in the future