novu 是做什么的？
Integrate Novu's in-app notification inbox into web applications. Supports React, Next.js, and vanilla JavaScript. Includes the Inbox component (bell icon + notification feed), composable components (Bell, Notifications, InboxContent, Preferences), headless hooks, branded theming, custom render props, multi-tenancy via contexts, tabs, localization, and HMAC security. Use when adding an in-app notification center, bell icon, notification feed, real-time notification updates, or building a pers...