Updates or creates person information associated with the authenticated phone number. This endpoint uses Phone OTP Tokens

Fields that can be updated:

• preferred_name: Required, non-empty string
• email_address: Optional, valid email format or null

Response includes all Person fields:

• id: The id of the person record
• preferred_name: The preferred name
• email_address: The email address (can be null)
• phone_number: The phone number associated with this person
• role: The person's role (defaults to 'CLIENT' for the primary portal user)
• allows_email: Whether email communication is allowed