refactor(nix): expose formatter wrapper in outputs

src/dotfiles/default.nix

@@ -45,15 +45,15 @@ let
   };
 in
 {
-  formatter.${system} = formatter;
+  formatter.${system} = formatter.config.build.wrapper;
 
   apps.${system} = import ./apps.nix {
     inherit
       inputs
       lib
-      formatter
       system
       ;
+    formatter = formatter.config.build.wrapper;
   };
 
   nixosConfigurations = import ./hosts.nix {

src/dotfiles/formatter.nix

@@ -1,5 +1,5 @@
 { inputs, system }:
-(inputs.treefmt-nix.lib.evalModule inputs.nixpkgs.legacyPackages.${system} {
+inputs.treefmt-nix.lib.evalModule inputs.nixpkgs.legacyPackages.${system} {
   projectRootFile = "flake.nix";
 
   programs.nixfmt.enable = true;
@@ -7,4 +7,4 @@
   settings.formatter.nixfmt.excludes = [
     "configs/nixos/hosts/*/hardware-configuration.nix"
   ];
-}).config.build.wrapper
+}