data model: type nixos module

Reviewed-on: fricklerhandwerk/Fediversity#6
Reviewed-by: Valentin Gagarin <valentin.gagarin@tweag.io>

deployment/data-model-test.nix

@@ -1,4 +1,5 @@
 let
+  sources = import ../npins;
   inherit (import ../default.nix { }) pkgs inputs;
   inherit (pkgs) lib;
   inherit (lib) mkOption types;
@@ -69,7 +70,11 @@ in
                       };
                     };
                     config = {
-                      resource-type = types.raw; # TODO: splice out the user type from NixOS
+                      resource-type = types.deferredModuleWith {
+                        staticModules = import "${sources.nixpkgs}/nixos/modules/module-list.nix" ++ [
+                          { _class = "nixos"; }
+                        ];
+                      };
                       apply =
                         requests:
                         let

deployment/data-model.nix

@@ -31,6 +31,7 @@ let
       inputs.nixops4.modules.nixops4Deployment.default
 
       {
+        _class = "nixops4Deployment";
         _module.args = {
           resourceProviderSystem = builtins.currentSystem;
           resources = { };
@@ -40,8 +41,6 @@ let
   };
 in
 {
-  _class = "nixops4Deployment";
-
   options = {
     resources = mkOption {
       description = "Collection of deployment resources that can be required by applications and policed by hosting providers";