add core mod

modules/default.nix

@@ -1,18 +1,30 @@
 {
   self,
   inputs,
-  config,
   ...
 }:
+let
+  mods = with self.nixosModules; [
+    user
+    packages
+    agenix
+    boot
+    core
+    /etc/nixos/hardware-configuration.nix
+  ];
+in
 {
   flake.nixosConfigurations.nerv = inputs.nixpkgs.lib.nixosSystem {
-    modules = with self.nixosModules; [
-      user
-      packages
-      agenix
-      boot
-      /etc/nixos/hardware-configuration.nix
-    ];
-    config.dualBoot = true;
+    modules =
+      with self.nixosModules;
+      [
+        {
+          config.dualBoot = true;
+        }
+      ]
+      ++ mods;
+  };
+  flake.nixosConfigurations.seele = inputs.nixpkgs.lib.nixosSystem {
+    modules = mods;
   };
 }