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-default-editor

@@ -59,4 +59,4 @@ fi
 mkdir -p "$(dirname "$editor_file")"
 printf '%s\n' "$editor" >"$editor_file"
 
-omarchy-notification-send -g $glyph "$name is now the default editor"
+omarchy-notification-send -g $glyph "$(omarchy-text "%1 is now the default editor" "$name")"