[KRAKENS ANALYTICS] Implement Email Verification

[geomachine]

Is your feature request related to a problem? Please describe.
Users can currently register without verifying their email, leading to fake accounts.

Describe the solution you'd like
Send verification links or OTP emails during registration and activate accounts only after confirmation.

Describe alternatives you've considered
Manual admin approval, but automated verification is scalable.

Additional context
Needs SMTP configuration and token expiration handling.