Enatega Customer Application: App isn't allowing a one-letter first name during sign-up and change Validation message accordingly

Is your feature request related to a problem? Please describe.

App isn't allowing a one-letter first name during sign-up.
Consider special cases where a single letter might be valid (e.g., some East Asian names).

Also change Validation message accordingly, under the first name field if user enters a single letter its showing a validation message Invalid First Name ! which isn't relevant to the field.

Describe the solution you'd like
The app is designed to allow one-letter first names (some cultures do have single-letter names, initials, or mononyms).
The business logic intentionally permits it for inclusivity.

Locate the customer sign-up and profile-name validation entry points in the application; no specific files or tests are named in the issue. Reproduce the single-letter first-name case, then verify that it is accepted and that the first-name validation message is accurate for invalid input.

Written by the indexing model from the issue text.