Add Simplified Chinese as a system language

The installer asks for the language before the keyboard, and
Setup > Language (omarchy language en|zh) switches it later. Under
zh_CN the menu reads its labels from omarchy-menu.zh-cn.jsonc, the
shell from I18nZh.js through I18n.tr, and notifications are worded
by their sender through omarchy-text, which reads the same table.
User text is never translated.

bin/omarchy-toggle-theme-sync

@@ -5,7 +5,7 @@
 omarchy-toggle herdr-theme-sync
 
 if omarchy-toggle-enabled herdr-theme-sync; then
-  omarchy-notification-send -g 󰸌 "Herdr theme sync enabled"
+  omarchy-notification-send -g 󰸌 "$(omarchy-text "Herdr theme sync enabled")"
 else
-  omarchy-notification-send -g 󰸌 "Herdr theme sync disabled"
+  omarchy-notification-send -g 󰸌 "$(omarchy-text "Herdr theme sync disabled")"
 fi