Nix flake update

nix/home.nix

@@ -10,7 +10,7 @@
   programs.home-manager.enable = true;
 
   # Enable integration with generic Linux OSs
-  targets.genericLinux.enable = pkgs.stdenv.isLinux;
+  targets.genericLinux.enable = pkgs.stdenv.hostPlatform.isLinux;
 
   home.packages = with pkgs; [
     # Better cat
@@ -28,6 +28,7 @@
     roboto-mono
     sops
     just
+    codex
   ];
 
   imports = [