feat: add support for shell configuration in preferences

hosts/hulk/users.nix

@@ -27,6 +27,6 @@ in
       "adbusers"
     ] ++ optional config.modules.nordvpn.enable [ "nordvpn" ];
     ignoreShellProgramCheck = true;
-    shell = pkgs.fish;
+    shell = preferredShell pkgs;
   };
 }

preferences.nix

@@ -4,6 +4,7 @@
       username = "sadorowo";
       fullname = "Franek";
       homeDirectory = "/home/${users.hulk.username}";
+      preferredShell = pkgs: pkgs.fish;
       isRoot = false;
     };
   };