refactor: localize settings sidebar tab names to Chinese

Rename the settings tabs to 通用设置 / 对象存储 / 远程主机 / 智能识图 so
the sidebar reads naturally for the primary Chinese audience.

frontend/src/App.vue

@@ -64,10 +64,10 @@ const activeTab = ref<SettingsTab>('general')
 // Sidebar entries are declarative so adding a destination type later is
 // a one-line change. The label values match the user-facing tab names.
 const sidebarItems: Array<{ id: SettingsTab; label: string }> = [
-  { id: 'general', label: 'General' },
-  { id: 's3', label: 'S3' },
-  { id: 'ssh', label: 'SSH' },
-  { id: 'llm', label: 'LLM' },
+  { id: 'general', label: '通用设置' },
+  { id: 's3', label: '对象存储' },
+  { id: 'ssh', label: '远程主机' },
+  { id: 'llm', label: '智能识图' },
 ]
 
 interface OverlayPayload {