refactor: centralize unfree package allowlists

Move all allowUnfreePredicate declarations to global configs to prevent
the "last definition wins" merging issue. Unfree packages are now managed
in two central locations:
- NixOS system packages: nixos/common/global/default.nix
- Home Manager packages: home-manager/sajenim/global/default.nix

home-manager/sajenim/features/editors/default.nix

@@ -37,14 +37,6 @@
       ])
     ]); # https://github.com/theCapypara/nix-jetbrains-plugins
 
-  # Allow unfree packages for proprietary software
-  nixpkgs.config.allowUnfreePredicate = pkg:
-    builtins.elem (lib.getName pkg) [
-      "claude-code"
-      "idea-ultimate"
-      "idea-ultimate-with-plugins" 
-    ];
-
   # Copy our configuration files to home directory
   home.file = {
     ".ideavimrc".source = ./ideavimrc;