Transfer wizard:
- Can now transfer between different programs (not just same-program)
- Program dropdown in step 2 to pick destination program
- Calculates price difference via PricingService
- If new program costs more, shows the difference and creates an invoice
- Success screen links to the created invoice

Collect payment wizard:
- Shows upcoming installments (from payment plans) with exact due dates
- Shows upcoming monthly renewal dates from enrollments
- Sorted by due_date so the most urgent appears first
- Invoices now sorted ASC by due_date (urgent first)
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>