zsh: escape named directory hashes

Named directory hash values are rendered into zsh code. Interpolating them inside double quotes is not enough for values containing quotes, glob syntax, or other shell metacharacters.

Render both the hash name and target with shell escaping so dirHashes entries are emitted as literal zsh arguments.

tests/modules/programs/zsh/zshrc-content-priorities.nix

@@ -8,6 +8,12 @@
       "/tmp/with space"
       "/tmp/with[glob]"
     ];
+    dirHashes = {
+      docs = "/tmp/with space";
+      glob = "/tmp/with[glob]";
+      home = "$HOME/Documents";
+      quoted = ''/tmp/with "quotes"'';
+    };
 
     initContent = lib.mkMerge [
       (lib.mkBefore ''
@@ -71,6 +77,12 @@
           # Default priority
           echo "Default priority content"
 
+          # Named Directory Hashes
+          hash -d docs="/tmp/with space"
+          hash -d glob="/tmp/with[glob]"
+          hash -d home="$HOME/Documents"
+          hash -d quoted="/tmp/with \"quotes\""
+
           zprof
           # Low priority (mkAfter)
           echo "Low priority content"