add codex and gemini-cli as native nix packages

modules/user/packages.nix

@@ -13,8 +13,8 @@
     # ── AI Coding Tools ──────────────────────────────────
     unstable.claude-code            # Claude Code CLI
     unstable.antigravity            # Antigravity IDE
-    # codex: install via `npm i -g @openai/codex` (not in nixpkgs)
-    # gemini-cli: install via `npm i -g @google/gemini-cli` (not in nixpkgs)
+    codex                           # OpenAI Codex CLI
+    gemini-cli                      # Google Gemini CLI
 
     # ── Terminals & Editors ──────────────────────────────
     alacritty                       # GPU-accelerated terminal
@@ -73,9 +73,5 @@
     dconf
   ];
 
-  # ── npm global tools (codex, gemini-cli) ────────────────
-  # These aren't in nixpkgs. Install once after first boot:
-  #   mkdir -p ~/.npm-global && npm config set prefix ~/.npm-global
-  #   npm i -g @openai/codex @google/gemini-cli
-  # PATH is set in shell.nix via ~/.npm-global/bin
+
 }

modules/user/shell.nix

@@ -62,9 +62,6 @@
     };
 
     initContent = ''
-      # npm global bin (codex, gemini-cli)
-      export PATH="$HOME/.npm-global/bin:$PATH"
-
       # Force Atuin up-arrow binding
       bindkey '^[[A' atuin-up-search
       bindkey '^[OA' atuin-up-search