[GIT-44] refactor(auth): add PASSWORD_TOO_WEAK error code

[JayashTripathy]

Description

This PR adds PASSWORD_TOO_WEAK error code and update related error handling in password change flow

Type of Change

• [x] Improvement (change that would cause existing functionality to not work as expected)
• [x] Code refactoring

Summary by CodeRabbit

• New Features

  • Added explicit "password too weak" error so the system recognizes and surfaces weak-password cases.

• Bug Fixes

  • Change-password flow now displays server-provided weak-password messages inline beneath the new password field and includes the error in banner alerts for clearer feedback.

_{✏️ Tip: You can customize this high-level summary in your review settings.}