use a more up-to-date flake for claude code, clean up system eval warn

home-manager/home.nix

@@ -9,7 +9,7 @@
 
   home.packages = with pkgs; [
     # Window manager & desktop environment
-    inputs.niri.packages.${pkgs.system}.niri
+    inputs.niri.packages.${pkgs.stdenv.hostPlatform.system}.niri
     swayidle
     swww
     kanshi
@@ -82,8 +82,8 @@
     gnome-boxes
 
     # AI development tools
-    claude-code
-    inputs.codex-cli-nix.packages.${pkgs.system}.default
+    inputs.claude-code-nix.packages.${pkgs.stdenv.hostPlatform.system}.default
+    inputs.codex-cli-nix.packages.${pkgs.stdenv.hostPlatform.system}.default
     gemini-cli
 
     # Internet & networking