feat: add codex

Author: kid

modules/nixfiles/ai/codex.nix

@@ -0,0 +1,13 @@
+{
+  nf.ai.codex = {
+    homeManager =
+      { pkgs, ... }:
+      {
+        programs.codex = {
+          enable = true;
+          enableMcpIntegration = true;
+          package = pkgs.llm-agents.codex;
+        };
+      };
+  };
+}