zsh: escape cdpath entries

Zsh cdpath is an array. Rendering entries by joining on spaces breaks paths containing spaces, glob characters, or other shell syntax.

Use the shared shell array formatter so each configured cdpath entry is emitted as a quoted array element.

modules/programs/zsh/default.nix

@@ -398,6 +398,9 @@ in
       dirHashesStr = concatStringsSep "\n" (
         lib.mapAttrsToList (k: v: ''hash -d ${k}="${v}"'') cfg.dirHashes
       );
+      # Keep double quotes so existing configs using shell variables like
+      # $HOME still expand, while escaping chars special inside them.
+      cdpathStr = concatStringsSep " " (map (v: ''"${lib.escape [ "\\" "\"" "`" ] v}"'') cfg.cdpath);
     in
     mkIf cfg.enable (
       lib.mkMerge [
@@ -520,7 +523,7 @@ in
 
             (lib.mkIf (cfg.cdpath != [ ]) (
               mkOrder 510 ''
-                cdpath+=(${concatStringsSep " " cfg.cdpath})
+                cdpath+=(${cdpathStr})
               ''
             ))