processRetroactiveRenewal() was setting paid_amount = total_amount when
status='paid' but not creating a payment record, causing fine_amount to
stay at 0 (calculator sees paid_amount == total_amount → skips the year).
Now creates a retroactive payment via createRetroactivePayment() before
setting paid_amount, ensuring payment_id is always populated.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>