Close all GL entry gaps across the accounting surface

- Stripe payments/refunds/chargebacks now post DR/CR entries (PaymentController)
- Vendor credit void now reverses the posted GL lines (VendorCreditsController)
- Gift certificate issue/redeem/void post GL to account 2500 GC Liability;
  FinancialReportService Trial Balance + Balance Sheet include GC liability and
  breakage income; P&L shows deferred revenue deduction and breakage income line
- Customer deposits now post DR Checking / CR 2300 on record, reverse on delete;
  invoice auto-apply uses DR 2300 / CR AR (not a second bank debit); draft
  invoice delete reverses deposit-apply GL before the AR reversal
- Deposit.DepositAccountId column added; account 2300 seeded via migration
- InvoicesController.ApplyCredit now posts DR Sales Discounts / CR AR,
  consistent with CreditMemosController.Apply
- IssueRefund (cash/card) posts DR AR / CR Bank and sets Refund.DepositAccountId;
  refund modal gains a bank account selector hidden for store-credit path
- CancelRefund (cash/card) reverses the IssueRefund GL entries
- LedgerService GetAccountLedgerAsync + ComputePriorBalanceAsync now include
  Refunds, CreditMemoApplications, VendorCreditApplications, GC Liability (2500),
  and Customer Deposits (2300) so account ledger view and RecalculateAllAsync
  produce correct balances
- Three EF migrations applied: SeedSalesDiscountsAccount, AccountingGapsPhase2,
  AccountingDepositsGL
- Unit tests updated for new IAccountBalanceService constructor params (200/200)

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

src/PowderCoating.Web/Controllers/VendorCreditsController.cs

@@ -195,6 +195,10 @@ public class VendorCreditsController : Controller
             foreach (var line in vc.LineItems)
                 await _accountBalanceService.CreditAsync(line.AccountId, line.Amount);
 
+            // Record posting date so Void() can reverse only if GL entries were actually made.
+            vc.PostedDate = DateTime.UtcNow;
+            await _unitOfWork.VendorCredits.UpdateAsync(vc);
+
             // Status stays Open — the credit is now in the GL but not yet applied to a bill
             await _unitOfWork.CompleteAsync();
         });
@@ -260,6 +264,12 @@ public class VendorCreditsController : Controller
 
     // ── Void ─────────────────────────────────────────────────────────────────
 
+    /// <summary>
+    /// Voids a vendor credit. If the credit was previously posted (PostedDate is set), reverses the
+    /// original GL entries: CR Accounts Payable / DR each expense line item, restoring both balances.
+    /// Only the unapplied RemainingAmount of AP is reversed — applied portions reduced bill balances
+    /// that are already settled and remain part of the immutable audit trail.
+    /// </summary>
     [HttpPost]
     [Authorize(Policy = AppConstants.Policies.CompanyAdminOnly)]
     [ValidateAntiForgeryToken]
@@ -267,7 +277,10 @@ public class VendorCreditsController : Controller
     {
         if (!AllowAccounting()) return RedirectToAction("Landing", "Reports");
 
-        var vc = await _unitOfWork.VendorCredits.GetByIdAsync(id);
+        var vc = (await _unitOfWork.VendorCredits.FindAsync(
+            v => v.Id == id, false,
+            v => v.LineItems))
+            .FirstOrDefault();
         if (vc == null) return NotFound();
 
         if (vc.Status == VendorCreditStatus.Applied)
@@ -276,9 +289,25 @@ public class VendorCreditsController : Controller
             return RedirectToAction(nameof(Details), new { id });
         }
 
-        vc.Status          = VendorCreditStatus.Voided;
-        vc.RemainingAmount = 0;
-        await _unitOfWork.CompleteAsync();
+        await _unitOfWork.ExecuteInTransactionAsync(async () =>
+        {
+            // Reverse GL only if Post() was previously called; unposted credits have no GL entries.
+            if (vc.PostedDate.HasValue && vc.RemainingAmount > 0)
+            {
+                // CR AP for the unapplied amount (undoes the debit made at Post time)
+                await _accountBalanceService.CreditAsync(vc.APAccountId, vc.RemainingAmount);
+
+                // DR each expense line proportionally (unapplied fraction of each line)
+                var applyRatio = vc.Total > 0 ? vc.RemainingAmount / vc.Total : 1m;
+                foreach (var line in vc.LineItems)
+                    await _accountBalanceService.DebitAsync(line.AccountId, line.Amount * applyRatio);
+            }
+
+            vc.Status          = VendorCreditStatus.Voided;
+            vc.RemainingAmount = 0;
+            await _unitOfWork.VendorCredits.UpdateAsync(vc);
+            await _unitOfWork.CompleteAsync();
+        });
 
         TempData["Success"] = $"Vendor credit {vc.CreditNumber} voided.";
         return RedirectToAction(nameof(Index));