Add home-manager

home/default.nix

@@ -0,0 +1,20 @@
+{ inputs, self, user, ...}: {
+  imports = [ inputs.home-manager.nixosModules.home-manager ];
+  home-manager = {
+    useUserPackages = true;
+    useGlobalPkgs= true;
+    extraSpecialArgs = { inherit inputs user; };
+    users.${user} = {
+      imports = [
+        ./programs/firefox
+      ];
+      firefox.enable = true;
+      home = {
+        username = "${user}";
+        homeDirectory = "/home/${user}";
+        stateVersion = "23.11";
+      };
+      programs.home-manager.enable = true;
+    };
+  };
+}

home/programs/firefox/default.nix

@@ -0,0 +1,9 @@
+{ pkgs, config, lib, inputs, user, ...}: {
+  options.firefox.enable = lib.mkEnableOption "Firefox";
+
+  config = lib.mkIf config.firefox.enable {
+    programs.firefox = {
+      enable = true;
+    };
+  };
+}