fix(i18n): complete Simplified Chinese core and plugin translations (#1542)

* fix(i18n): complete Chinese onboarding and navigation labels

* fix(i18n): translate remaining Chinese core and plugin interfaces

* fix(i18n): translate host editor tab overflow controls

* fix(i18n): use consistent Chinese fleet terminology

* fix(i18n): localize hardcoded controls and plugin views

* fix(i18n): translate built-in homepage widget catalog

* test(homepage): follow translated timezone placeholder

* fix(i18n): translate plugin-provided homepage widgets

* fix(i18n): localize feature settings section titles

plugins/ai/locales/en.json

@@ -115,5 +115,8 @@
   },
   "hosts": {
     "docsLink": "View docs"
+  },
+  "plugin": {
+    "name": "AI Assistant"
   }
 }