- Add `ErrorBoundary` component to handle rendering fallback UI during errors.
- Integrate `ErrorBoundary` into main layout and critical pages for global error handling.
- Create `useErrorHandler` hook to handle async errors consistently across components.
- Refactor `NewCustomerModal` and `CustomersPage` to leverage `useErrorHandler` for improved error management.
- Add a fallback dialog UI for user-friendly error reporting and resolution.
