Is your feature request related to a problem? Please describe.
Currently, passphrase inputs in Sietch lack a consistent user-facing validation UI. While the backend validation exists (in internal/ui/passphrase.go), users are not provided with clear feedback about the strength or validity of their passphrases. This can lead to confusion and weaker security practices.

Describe the solution you'd like
Enhance the UI to display real-time validation feedback when users enter a passphrase. This should include:

• Minimum length indicator
• Character set requirements (uppercase, lowercase, digits, symbols)
• Warnings for common/insecure passwords
• A strength meter (weak/medium/strong)

Additional context
The backend validation system already handles passphrase rules. This issue focuses on updating the UI so users get immediate feedback when entering their passphrase, improving usability and encouraging stronger security practices.

Current State