- Add `onCustomerCreated` callback to refresh customer list after creation.
- Integrate `showInfoToast` and `showSuccessToast` for validation and creation feedback.
- Prevent closing modal on backdrop click; add explicit cancel button.
- Refactor `addCustomer` to use `callApi` and centralized routes.
- Simplify customer fetching logic in `CustomersPage` with reusable function.
- 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.
