fix: fall back to ys on any machine without powerlevel10k

The fallback was written for the server role only, so the Mac - which also runs
ys and also has no p10k - dropped through to oh-my-zsh's default theme instead.
A silent downgrade of the prompt on a machine that was working fine.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

.config/zsh/rc.d/05-pre-omz.zsh

@@ -12,9 +12,11 @@
 
 if [[ -d "${ZSH_CUSTOM:-$ZSH/custom}/themes/powerlevel10k" ]]; then
   ZSH_THEME="powerlevel10k/powerlevel10k"
-elif [[ "$ROLE" == "server" ]]; then
-  # What shron already used. Without this it would silently fall back to
-  # oh-my-zsh's default, which is a change nobody asked for.
+else
+  # ys is what both machines without powerlevel10k already ran. Without this
+  # they fall through to oh-my-zsh's default, which is a change nobody asked
+  # for - the Mac did exactly that on the first attempt, where this fallback
+  # was written for the server role only.
   ZSH_THEME="ys"
 fi