Move system/home/default.nix into system/default.nix,
system/home/desktop/default.nix into system/desktop.nix to reduce
unnecessary duplication. Moved everything in home/desktop up to home/
and adjusted paths accordingly. Moved wallpapers up to system/ since
it makes sense with where it's used.
Merge allowUnfreePredicate into single place again since it seems to
override rather than combine if used multiple times.
Install NoMachine on all machines again by default.
Move stylix config up to flake.nix as config wouldn't build without it,
also move wallpapers directory up to top level to match
Only enable git-sync where it's defined, rather than in home/default.nix
Move commonModule into system/default.nix
Keep most essential parts (user definition, home-manager init) in
flake.nix but move rest to system/default.nix
Remove some tui expressions from home and add all to home/default.nix,
will always want those so always use
Disable gamescope session unless gamescope.nix imported
Move various home.package definitions to environment.systemPackage in
system/ expressions, located based on appropriate use
Move wallpapers directory due to restructure, no other changes to it