feat: Implement S2A account cleaner management and a global application configuration context, with supporting backend API.

frontend/src/context/ConfigContext.tsx

@@ -61,6 +61,11 @@ export function ConfigProvider({ children }: { children: ReactNode }) {
     refreshConfig()
   }, [refreshConfig])
 
+  // 当站点名称变化时，更新浏览器标签页标题
+  useEffect(() => {
+    document.title = siteName
+  }, [siteName])
+
   // Update S2A client when config changes and auto-test connection
   useEffect(() => {
     if (config.s2a.apiBase && config.s2a.adminKey) {