Enatega Admin-Dashboard + Customer: Ensure Consistent Naming for "Voucher" and "Coupons"

Issue:
The terms "Voucher" and "Coupons" are used interchangeably in the system, leading to inconsistency and potential confusion for users.

Impact:

Users may not clearly understand whether "Voucher" and "Coupons" refer to the same feature or different functionalities.
Inconsistent naming can create confusion in the UI, documentation, and communication.
It may affect API responses, database fields, or reports if both terms are used inconsistently in different places.

Recommendation:

Choose a single, consistent term: either "Voucher" or "Coupon."
Update all instances of the term across the UI, API, documentation, and database schema.
Ensure consistency in user-facing messages, buttons, forms, and reports.
Communicate the change to relevant teams to maintain uniformity in future development.

No files, tests, or entry points are identified in the issue, so first locate every use of "Voucher" and "Coupon" across the backend repository and related UI, API, documentation, and schema references. Confirm which term is selected and consider the work complete when the chosen term is used consistently in user-facing text, API responses, database fields, reports, and documentation.

Written by the indexing model from the issue text.