Convert non-deposit payments to customer credits on invoice void

When voiding an invoice that has non-deposit payments (e.g. CC charges),
those payments are now converted to CRED- Deposit records so the money
trail is preserved and the credit auto-applies to the replacement invoice.
Deposits that were applied to the voided invoice are also re-released so
they can auto-apply again. Void confirmation dialog and success message
both reflect the credit amount when applicable.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/PowderCoating.Web/Views/Invoices/Details.cshtml

@@ -28,6 +28,9 @@
     var onlinePaymentsEnabled = ViewBag.OnlinePaymentsEnabled == true;
     var showOnlinePaymentCard = !isDraft && !isVoided && Model.BalanceDue > 0 && onlinePaymentsEnabled;
     var guidedActivationCallout = ViewBag.GuidedActivationCallout as PowderCoating.Web.ViewModels.GuidedActivation.GuidedActivationCalloutViewModel;
+    var nonDepositPaymentTotal = Model.Payments
+        .Where(p => !(p.Reference ?? "").StartsWith("Deposit "))
+        .Sum(p => p.Amount);
 }
 
 <div class="row justify-content-center">
@@ -694,7 +697,9 @@
                             @if (!isVoided && Model.Status != InvoiceStatus.Paid)
                             {
                                 <form asp-action="Void" asp-route-id="@Model.Id" method="post"
-                                      onsubmit="return confirm('Void this invoice? This will reverse the remaining balance on the customer account.')">
+                                      onsubmit="return confirm('@(nonDepositPaymentTotal > 0
+                                          ? $"Void this invoice? {nonDepositPaymentTotal.ToString("C")} in payments will be converted to a customer credit and auto-applied to the next invoice."
+                                          : "Void this invoice? This will reverse the remaining balance on the customer account.")')">
                                     @Html.AntiForgeryToken()
                                     <button type="submit" class="btn btn-outline-warning w-100">
                                         <i class="bi bi-x-circle me-2"></i>Void Invoice