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.

shell/plugins/panels/elsewhen/HeroTitle.qml

@@ -73,7 +73,7 @@ Column {
     anchors.horizontalCenter: parent.horizontalCenter
     spacing: Style.space(9)
 
-    TitleWord { text: "World" }
+    TitleWord { text: I18n.tr("World") }
 
     Item {
       id: heroIcon
@@ -151,7 +151,7 @@ Column {
       }
     }
 
-    TitleWord { text: "Clock" }
+    TitleWord { text: I18n.tr("Clock") }
   }
 
   component TitleWord: Text {