- S-01: Extract _EMAIL_REGEX, _validate_email_format, _validate_name_field
shared helpers in schemas/auth.py — used by RegisterRequest, ProfileUpdate,
and admin.CreateUserRequest (eliminates 3x duplicated regex)
- S-04: Migration 038 replaces plain unique constraint on email with a
partial unique index WHERE email IS NOT NULL
- Email is now required on registration (was optional)
- Date of birth is now required on registration, editable in settings
- User model gains date_of_birth (Date, nullable) column
- ProfileUpdate/ProfileResponse include date_of_birth
- Registration form adds required Email, Date of Birth fields
- Settings Profile card adds Date of Birth input (save-on-blur)
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>