Add codex-acp overlay

nix/flake.nix

@@ -16,6 +16,7 @@
     pkgsForSystem = (system: import nixpkgs {
       inherit system;
       config.allowUnfree = true;
+      overlays = [ (import ./overlays/codex-acp.nix) ];
     });
 
     mkHomeConfig = ({system, username ? "ttm" }: home-manager.lib.homeManagerConfiguration {
@@ -34,6 +35,7 @@
     });
   in
     utils.lib.eachDefaultSystem (system: {
+      packages.codex-acp = (pkgsForSystem system).codex-acp;
       legacyPackages.homeConfigurations.std = mkHomeConfig { inherit system; };
     });
 }