Add Codex module and skills, update Helium

Enable Codex on Garand-Desktop and Garand-Laptop.
Keep it disabled on the default host.

Add a new `codex.nix` module and import it in the home
configuration. Introduce a shared `skills.nix` module that
downloads Ponytail and Caveman skill files for both
`.agents/skills` and `.codex/skills`. Update Helium to
0.19.3.1 with the correct hash. Remove the obsolete Zed
skills module.

hosts/Garand-Desktop/home-modules.nix

@@ -8,6 +8,7 @@ _: {
     remote-server.enable = false; # Remote Server: enable remote editing capabilities
   };
   opencode.enable = false; # OpenCode: terminal coding agent
+  codex.enable = true; # Codex: Lightweight coding agent that runs in your terminal
   ollama.enable = false; # Ollama: Local Llms
 
   /*

hosts/Garand-Laptop/home-modules.nix

@@ -8,6 +8,7 @@ _: {
     remote-server.enable = false; # Remote Server: enable remote editing capabilities
   };
   opencode.enable = false; # OpenCode: terminal coding agent
+  codex.enable = true; # Codex: Lightweight coding agent that runs in your terminal
   ollama.enable = false; # Ollama: Local Llms
 
   /*

hosts/default/home-modules.nix

@@ -8,6 +8,7 @@ _: {
     remote-server.enable = false; # Remote Server: enable remote editing capabilities
   };
   opencode.enable = false; # OpenCode: terminal coding agent
+  codex.enable = false; # Codex: Lightweight coding agent that runs in your terminal
   ollama.enable = false; # Ollama: Local Llms
 
   /*

modules/core/packages/appimages/helium.nix

@@ -4,8 +4,8 @@
   fetchurl,
 }: let
   pname = "helium";
-  version = "0.19.2.1";
-  hash = "sha256-oEVQo8fHC9rTrNOkQw7ajSr8C/cXOpxYpAP+q5UXCH8=";
+  version = "0.19.3.1";
+  hash = "sha256-Rg5tKlyG0DkhYkItGyF6NmMb2DD40h5WUYyWAgl5eQY=";
 
   src = fetchurl {
     url = "https://github.com/imputnet/helium-linux/releases/download/${version}/helium-${version}-x86_64.AppImage";
@@ -36,4 +36,3 @@ in
       maintainers = with lib.maintainers; [garand_plg];
     };
   }
-# https://github.com/imputnet/helium-linux/releases/download/0.11.7.1/helium-0.11.7.1-x86_64.AppImage

modules/home/codex.nix

@@ -0,0 +1,17 @@
+{
+  pkgs,
+  lib,
+  config,
+  ...
+}: {
+  options.codex.enable = lib.mkEnableOption "Codex";
+
+  config.programs.codex = lib.mkIf config.codex.enable {
+    enable = true;
+    package = pkgs.codex;
+    # skills = {
+    #   ponytail = /home/${username}/.agents/skills/ponytail;
+    #   caveman = /home/${username}/.agents/skills/caveman;
+    # };
+  };
+}

modules/home/default.nix

@@ -19,6 +19,7 @@ _: {
     ./btop.nix
     ./cargo.nix
     ./cava.nix
+    ./codex.nix
     ./easyeffects.nix
     ./eza.nix
     ./fzf.nix
@@ -37,6 +38,7 @@ _: {
     ./opencode.nix
     ./prismlauncher.nix
     ./qt.nix
+    ./skills.nix
     ./ssh.nix
     ./starship.nix
     ./stylix.nix

modules/home/skills.nix

@@ -0,0 +1,27 @@
+{
+  pkgs,
+  # lib,
+  ...
+}: let
+  skillPath = ".agents/skills";
+  skillCodexPath = ".codex/skills";
+  urlDomain = "https://raw.githubusercontent.com";
+  refs = "refs/heads/main/skills";
+
+  ponytailSkill = pkgs.fetchurl {
+    url = "${urlDomain}/DietrichGebert/ponytail/${refs}/ponytail/SKILL.md";
+    sha256 = "sha256-IiTh4N3bHhJtER4HYPEFEo1g9Ro703TiPA5Tigv7k3s=";
+  };
+
+  cavemanSkill = pkgs.fetchurl {
+    url = "${urlDomain}/JuliusBrussee/caveman/${refs}/caveman/SKILL.md";
+    sha256 = "sha256-447Gcey+5HziNBkL4SYV2vYKxmfXdbc0DUnQf09jx7w=";
+  };
+in {
+  home.file = {
+    "${skillPath}/ponytail/SKILL.md".source = ponytailSkill;
+    "${skillPath}/caveman/SKILL.md".source = cavemanSkill;
+    "${skillCodexPath}/ponytail/SKILL.md".source = ponytailSkill;
+    "${skillCodexPath}/caveman/SKILL.md".source = cavemanSkill;
+  };
+}

modules/home/zed/default.nix

@@ -19,6 +19,5 @@
     ./user-settings
     ./extensions.nix
     ./extra-packages.nix
-    ./skills.nix
   ];
 }

modules/home/zed/skills.nix

@@ -1,20 +0,0 @@
-{
-  pkgs,
-  # lib,
-  ...
-}: let
-  skillPath = ".agents/skills";
-  urlDomain = "https://raw.githubusercontent.com";
-  refs = "refs/heads/main/skills";
-in {
-  home.file = {
-    "${skillPath}/ponytail/SKILL.md".source = pkgs.fetchurl {
-      url = "${urlDomain}/DietrichGebert/ponytail/${refs}/ponytail/SKILL.md";
-      sha256 = "sha256-IiTh4N3bHhJtER4HYPEFEo1g9Ro703TiPA5Tigv7k3s=";
-    };
-    "${skillPath}/caveman/SKILL.md".source = pkgs.fetchurl {
-      url = "${urlDomain}/JuliusBrussee/caveman/${refs}/caveman/SKILL.md";
-      sha256 = "sha256-447Gcey+5HziNBkL4SYV2vYKxmfXdbc0DUnQf09jx7w=";
-    };
-  };
-}