Allow access to the main home manager user directly

modules/user/default.nix

@@ -1,9 +1,15 @@
-{ system, inputs, config, pkgs, ... }: let
+{ system, inputs, config, lib, pkgs, ... }: let
   username = "admin";
   homeDirectory = "/home/${username}";
 in {
   imports = [ inputs.home-manager.nixosModules.home-manager ];
 
+  options.user = lib.mkOption {
+    type = with lib.types; attrsOf anything;
+    default = {};
+  };
+
+  config = {
     users.users.${username} = {
       isNormalUser = true;
       uid = 1000;
@@ -52,16 +58,23 @@ in {
     home-manager = {
       extraSpecialArgs = {
         inherit system inputs;
-      systemConfig = config;
       };
 
       # use system nixpkgs instead of home-manager nixpkgs
       useGlobalPkgs = true;
 
-    users.${username} = { system, inputs, systemConfig, pkgs, ... }: {
+      users.${username} = config.user;
+    };
+
+    # pass the user config as a system module argument
+    _module.args = {
+      homeConfig = config.home-manager.users.${username};
+    };
+
+    user = {
       home = {
         inherit username homeDirectory;
-        stateVersion = systemConfig.system.stateVersion;
+        stateVersion = config.system.stateVersion;
       };
     };
   };