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/wifiqr/Panel.qml

@@ -183,7 +183,7 @@ Item {
       if (exitCode !== 0 || root.qrSize === 0) {
         root.qrSize = 0
         root.qrRows = []
-        if (root.error === "") root.error = "Could not generate the Wi-Fi QR code"
+        if (root.error === "") root.error = I18n.tr("Could not generate the Wi-Fi QR code")
       }
     }
   }
@@ -206,7 +206,7 @@ Item {
       if (root.pwExpectedStop) return
       if (!root.opened) return
       if (exitCode === 0 && root.password !== "") root.passwordVisible = true
-      else root.passwordError = "Could not read the Wi-Fi password"
+      else root.passwordError = I18n.tr("Could not read the Wi-Fi password")
     }
   }
 
@@ -305,7 +305,8 @@ Item {
 
           Text {
             visible: root.loading
-            text: "Generating QR code…"
+            textFormat: Text.PlainText
+            text: I18n.tr("Generating QR code…")
             color: root.onScrimDim
             font.family: root.fontFamily
             font.pixelSize: Style.font.bodySmall
@@ -328,7 +329,8 @@ Item {
 
           Text {
             visible: root.showingQr
-            text: "Scan to join this network"
+            textFormat: Text.PlainText
+            text: I18n.tr("Scan to join this network")
             color: root.onScrimDim
             font.family: root.fontFamily
             font.pixelSize: Style.font.bodySmall
@@ -341,7 +343,7 @@ Item {
             visible: root.showingQr && root.secured
             text: root.passwordError !== "" ? root.passwordError
               : root.passwordVisible ? root.password
-              : "Show password"
+              : I18n.tr("Show password")
             color: root.passwordError !== "" ? root.onScrimUrgent : root.onScrim
             opacity: root.passwordVisible || root.passwordError !== "" ? 1 : 0.6
             font.family: root.fontFamily