phsl / new-api

This commit introduces the following changes:

- Create a reusable NoticeModal component to handle system announcements
- Extract notice functionality from Home and HeaderBar components
- Add loading and empty states using Semi UI illustrations
- Implement "close for today" feature with localStorage
- Support both light and dark mode for empty state illustrations
- Add proper error handling and loading states
- Improve code reusability and maintainability

Breaking changes: None
Related components: HeaderBar.js, Home/index.js, NoticeModal.js