Move scripts to pkgs

[Ratakor]

Revival of #10 and #13

what's missing:

• some scripts to migrate to pkgs.scripts or to replace/remove
• correct usage of pkgs.scripts (override plumber, use in wrappers.yazi, ...)
• figure out what to do with deps (also writeShellApplication is often overkill)
• move user/scripts to user/packages/scripts.nix
• fix dependencies rebuild
• build docs CI smh depends on wallpapers now