Users may wish to change the default value of override and nixos
inputs. If they do so, we want the registry listing to reflect the
proper ref names afterwards.
Also create a shell alias to easily search every flake in nix.registry.
* Import attrs of profiles automatically with `defaultImport`.
* Refactor profiles to ensure all are functions returning a module.
* Add a suites.nix with collections of profiles.
* Add suites as `specialArgs` to modules.
* Add suite import to NixOS host.
* fix nixos-option
* use flake-compat for all backward compat concerns
* rebuild devshell after any nix file changes
* reexport system pkgs as legacyPackages
* provide lib flake output
* provide flake lib to nixos configs via `lib.flk`
* clean up flake.nix
