- InstallmentCalculator: calculateEarlySettlement() sums all pending principal and interest separately; settlement_amount = principal only, all interest waived
- InstallmentController: earlySettlement() (confirmation page), processEarlySettlement() (executes: single PaymentService call, zeros interest on each settled row, marks plan completed + is_cash_settled=1, dispatches installment.early_settled), settlementReceipt() (print view)
- Routes: GET/POST /installments/{id}/early-settlement, GET /installments/{id}/settlement-receipt/{receiptId}
- show.php: ⚡ تسوية مبكرة button (requires installment.pay permission, only when active + pending > 0)
- early_settlement.php: breakdown table (original due / interest waived / principal to pay), pending items preview, mandatory confirmation checkbox, submit disabled until checked
- settlement_receipt.php: print-ready receipt showing original balance, interest waived, amount paid, settled items list, amount in words, stamp/signature area
- PaymentService: early_settlement payment type label
- Architecture Map: section 5.6, new route rows, new event row
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>