add mkSystem and dev.nix

.envrc

@@ -1,2 +1,2 @@
 use flake
-watch_file flake.nix
+watch_file dev.nix

dev.nix

@@ -0,0 +1,14 @@
+{
+  perSystem = {pkgs, ...}: {
+    devShells.default = pkgs.mkShell {
+      packages = with pkgs; [
+        alejandra
+        fzf
+        just
+        nil
+      ];
+    };
+
+    formatter = pkgs.alejandra;
+  };
+}

flake.nix

@@ -41,42 +41,33 @@
     flake-parts.lib.mkFlake {inherit inputs;} {
       systems = ["x86_64-linux"];
 
+      imports = [./dev.nix];
+
       flake = let
-        mkSystem = name:
+        mkSystem = modules: name:
           nixpkgs.lib.nixosSystem {
             system = "x86_64-linux";
-            modules = [
-              ./common.nix
-
+            modules =
+              [
                 ./${name}
                 ./${name}/hardware-configuration.nix
 
                 {networking.hostName = name;}
+              ]
+              ++ modules;
+            specialArgs = inputs;
+          };
 
+        mkDesktop = mkSystem [
+          ./common.nix
           lanzaboote.nixosModules.lanzaboote
           home-manager.nixosModules.home-manager
         ];
-            specialArgs = inputs;
-          };
       in {
-        nixosConfigurations = nixpkgs.lib.genAttrs ["fuji" "kilimandjaro"] mkSystem;
+        nixosConfigurations = {
+          fuji = mkDesktop "fuji";
+          kilimandjaro = mkDesktop "kilimandjaro";
         };
-
-      perSystem = {system, ...}: let
-        pkgs = import nixpkgs {
-          inherit system;
-        };
-      in {
-        devShells.default = pkgs.mkShell {
-          packages = with pkgs; [
-            alejandra
-            fzf
-            just
-            nil
-          ];
-        };
-
-        formatter = pkgs.alejandra;
       };
     };
 }