Enatega Admin-dashboard: Unable to add a new Staff to the admin dashboard

### Describe the bug
When attempting to add a new Staff through the admin dashboard, the system fails to register the staff. The new staff does not appear in the staff list, and no confirmation message is shown.

Steps to Reproduce:

1. Open the Admin Dashboard.
2. Navigate to the Staff Management section.
3. Click on the Add New Staff button.
4. Fill in the required staff details.
5. Click Save or Submit.
6. Observe that the new staff is not added to the list.

Desktop (please complete the following information):

> OS: [e.g. Windows]
> Browser [e.g. chrome]
> Version [e.g. Latest]

Start by reproducing the failure through the Admin Dashboard's Staff Management section using the Add New Staff flow. Inspect the entry point for saving staff details and trace why the staff list and confirmation message do not update. Done means a valid new staff member appears in the list and a confirmation is shown.

Written by the indexing model from the issue text.