zsh: add homebrew path on macos

roles/home/zsh.nix

@@ -1,4 +1,4 @@
-{ pkgs, ... }:
+{ pkgs, lib, stdenv, ... }:
 
 {
   home.packages = with pkgs; [ any-nix-shell ];
@@ -21,6 +21,8 @@
 
       any-nix-shell zsh --info-right | source /dev/stdin
       source ${pkgs.nix-index}/etc/profile.d/command-not-found.sh
+    '' + lib.optional (stdenv.isDarwin) ''
+      export PATH=$PATH:/opt/homebrew/bin
     '';
   };
 }