- VAT % now reads default from RENTAL_VAT_PCT business rule (seeded at 1%);
  contract form pre-fills with live rule value instead of hardcoded 1
- Deposit row in contract_show now shows payment reference (receipt number)
  when deposit_payment_id is set
- Bulk invoice generation: POST /contracts/{id}/invoices/bulk-generate
  generates all monthly invoices from start to end date, skipping existing;
  button added to page_actions and invoices table header with JS confirm
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>