feat: enhance authentication flow with improved error handling and validation

Feature Request Template

Title (semantic)

• Format: feat(scope): short description

Description

This merge request implements some minor fixes, refactoring and features.

Checklist

• The feature has been fully implemented.
• Tests for the new feature are included and passing.
• User documentation/guides have been updated (if applicable).
• Impact on existing functionality has been considered.

Related Issue(s)

Closes #