Fix: Restore former window fullscreen state after screensaver exit

[MGross21]

Summary

Addresses #3218 by @rmusaev99.

Currently the fullscreen launch of the screensaver will override any former full-screen windows and will not return them to their state upon closing.

Changes:

• Capture the former window and full-screen status
• Upon shutdown, revert focus to the prior window and restore full-screen status (1 and 2)
• Added null-safe jq defaults (//) to try and prevent any errors from launching screensaver from blank workspaces.

Testing

I was able to test the individual commands using my custom instance of Hyprland on a laptop, but I was not able to get an instance of Omarchy running in a VM. Would be very appreciative if someone could test the changes on their own instance. Happy to make whatever tweaks are required to confirm this works on single-monitor and multi-monitor systems as well as small taste-related code changes.

Other Approach

I have also experimented with the idea of forcing the screensaver to run on uniquely-named special workspaces, such as iterating over all monitors and running:

hyprctl dispatch togglespecialworkspace "screensaver-${MONITOR-NAME}"

This way, there is no conflict or need for reverting the state of any former windows on teardown. If this is something that would like to be looked into, I would be happy to make additional changes or open another PR.