feat(settings): 轻应用登录参数与界面模式管理员默认

- 登录时从路由参数 yUserId/access_token 获取并存入 userInfo
- 轻应用管理页路由参数新增 userName/gateDepartName/typeName 选项
- 添加系统默认界面模式设置（管理员可指定全量/简洁）
- useLayoutMode hook 支持优先级：用户自选 > 管理员默认 > 会话级

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

frontend-web/src/core/system-settings/hooks.ts

@@ -21,6 +21,7 @@ import {
   type PrivateSquareUpdate,
   type PromptPrefixUpdate,
   type PublishSquaresUpdate,
+  type LayoutMode,
   type ViewMode,
 } from "./api";
 
@@ -143,6 +144,27 @@ export function useViewMode(
   return [mode, setMode];
 }
 
+/**
+ * Effective interface layout mode (full chrome vs compact). A user's own choice
+ * (persisted in local settings) wins; otherwise the admin-configured system
+ * default applies; otherwise `undefined` (callers fall back to the session-level
+ * `sidebarEnabled` flag set by portal / yUserId login). `setMode` persists the
+ * user's override locally.
+ */
+export function useLayoutMode(): [
+  LayoutMode | undefined,
+  (mode: LayoutMode) => void,
+] {
+  const [settings, setSettings] = useLocalSettings();
+  const { data: appearance } = useAppearanceSettings();
+  const userOverride = settings.display.layoutMode;
+  const adminDefault = appearance?.default_layout_mode;
+  const mode = userOverride ?? adminDefault;
+  const setMode = (next: LayoutMode) =>
+    setSettings("display", { layoutMode: next });
+  return [mode, setMode];
+}
+
 export function useCitationDisplaySettings() {
   return useQuery({
     queryKey: CITATION_DISPLAY_KEY,