Form now collects for spouses: date_of_birth, nationality, marriage_date,
join_date, payment_date. For children: date_of_birth, join_date.

Validates spouse minimum age (SPOUSE_MIN_AGE rule, default 21) and
requires marriage_date. Non-Egyptian spouses get addition_fee calculated
as SPOUSE_FOREIGN_FEE% of current plan price at completion time.

TransferProcessor now uses submitted dates instead of defaults and stores
nationality and addition_fee on the spouse record.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>