Add a widget that shows password strength when entering a new password

We’ve all seen these before. This will at least encourage people to use better passwords.

Mentioned in https://cheatsheetseries.owasp.org/cheatsheets/Authentication_Cheat_Sheet.html#implement-proper-password-strength-controls

https://github.com/dropbox/zxcvbn suggested by OWASP (there’s a couple of Java versions)

Start with the OWASP Authentication Cheat Sheet section linked in the issue and review the suggested Dropbox zxcvbn library and Java alternatives. The issue does not name files or tests; clarify the supported password-entry screens, library choice, strength criteria, and UI expectations before implementation. Done means a password-strength widget appears while entering a new password.

Written by the indexing model from the issue text.