fix installment for carry over balance parent account

app/Views/payment/manual_pay.php

@@ -423,6 +423,7 @@
                     data-display-total="<?= esc($invoice['display_total'] ?? $invoice['total_amount'] ?? '') ?>"
                     data-balance-due-cents="<?= (int)($invoice['balance_due_cents'] ?? 0) ?>"
                     data-customer-credit-cents="<?= (int)($invoice['customer_credit_cents'] ?? 0) ?>"
+                    data-carry-forward-invoice="<?= !empty($invoice['is_carry_forward_invoice']) ? '1' : '0' ?>"
                     data-next-installment="<?= (int)($invoice['next_installment'] ?? 1) ?>">
                     <?php
                       $uiPaid  = (float)($invoice['paid_amount'] ?? 0);
@@ -634,6 +635,11 @@
       return isFinite(v) ? v : 1;
     }
 
+    function selectedInvoiceRequiresCarryForwardFull() {
+      const opt = currentOpt();
+      return carryForwardFullRequired || (opt && opt.getAttribute('data-carry-forward-invoice') === '1');
+    }
+
     function monthsUntil(endYmd) {
       if (!endYmd) return 0;
       const today = new Date();
@@ -788,12 +794,15 @@
 
       if (m === 'card') {
         forceCardRules();
-      } else if (carryForwardFullRequired) {
+      } else if (selectedInvoiceRequiresCarryForwardFull()) {
         forceCarryForwardFullRules();
       } else {
         // enable full/installment select
-        $type().removeAttribute('disabled');
-        $type().value = 'full';
+        const type = $type();
+        type.removeAttribute('disabled');
+        const installmentOption = type.querySelector('option[value="installment"]');
+        if (installmentOption) installmentOption.disabled = false;
+        type.value = 'full';
         $instSec().style.display = 'none';
         $instSeqRow().style.display = 'none';
         $amount().removeAttribute('readonly');
@@ -810,7 +819,7 @@
         forceCardRules();
         return;
       }
-      if (carryForwardFullRequired) {
+      if (selectedInvoiceRequiresCarryForwardFull()) {
         forceCarryForwardFullRules();
         return;
       }
@@ -834,7 +843,7 @@
 
       if (($method().value || '').toLowerCase() === 'card') {
         forceCardRules();
-      } else if (carryForwardFullRequired) {
+      } else if (selectedInvoiceRequiresCarryForwardFull()) {
         forceCarryForwardFullRules();
       } else {
         updateAmountHint();
@@ -908,7 +917,7 @@
           alert('Please enter a valid amount > 0.');
           return;
         }
-        if (carryForwardFullRequired && type === 'installment') {
+        if (selectedInvoiceRequiresCarryForwardFull() && type === 'installment') {
           alert(carryForwardFullMessage);
           return;
         }
@@ -924,7 +933,7 @@
 
         const newBal = (isFinite(balance) && isFinite(amount)) ? (balance - amount) : NaN;
         const overpay = (isFinite(newBal) && newBal < -0.005);
-        if (carryForwardFullRequired && isFinite(balance) && Math.abs(amount - balance) > 0.005) {
+        if (selectedInvoiceRequiresCarryForwardFull() && isFinite(balance) && Math.abs(amount - balance) > 0.005) {
           alert(carryForwardFullMessage);
           $amount().value = Math.max(0, balance).toFixed(2);
           return;