feat: 更新主题配置与系统设置

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

@@ -291,6 +291,8 @@ export type CustomThemeBaseMode = "light" | "dark";
 
 export interface CustomThemeColorOverrides {
   button_hover?: string | null;
+  navigation_gradient_start?: string | null;
+  navigation_gradient_end?: string | null;
   selected_background?: string | null;
   border?: string | null;
   muted?: string | null;