fix(pos-dashboard): show payment method names instead of order status

GetPosDashboardQuery payment breakdown SQL was grouping by
order_statuses.name (e.g. "Completed") instead of orders.payment_method
(e.g. "cash", "card", "qr", "transfer").

Fix: GROUP BY o.payment_method with COALESCE for empty values.
Frontend: apply MapPaymentMethodLabel() to translate method names
to Vietnamese (Tiền mặt, Thẻ, Mã QR, Chuyển khoản).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

apps/web-client-tpos-net/src/WebClientTpos.Client/Pages/Pos/Cafe/CafeDesktop.razor

@@ -547,7 +547,7 @@
                                 {
                                     <div class="pos-dashboard__payment-row">
                                         <div class="pos-dashboard__payment-header">
-                                            <span>@p.Method</span>
+                                            <span>@MapPaymentMethodLabel(p.Method)</span>
                                             <span style="font-weight:600;">@FormatPrice(p.Amount)</span>
                                         </div>
                                         <div class="pos-dashboard__payment-bar">

services/order-service-net/src/OrderService.API/Application/Queries/GetPosDashboardQuery.cs

@@ -140,18 +140,17 @@ public class GetPosDashboardQueryHandler : IRequestHandler<GetPosDashboardQuery,
 
         var popularItems = (await _connection.QueryAsync<PopularItemDto>(popularSql, parameters, commandTimeout: 5)).AsList();
 
-        // EN: Payment breakdown by status / VI: Phân tích theo trạng thái
+        // EN: Payment breakdown by payment method / VI: Phân tích theo hình thức thanh toán
         var paymentSql = @"
             SELECT
-                os.name AS Method,
+                COALESCE(NULLIF(o.payment_method, ''), 'unknown') AS Method,
                 COUNT(*) AS Count,
                 COALESCE(SUM(o.total_amount), 0) AS Amount
             FROM orders o
-            INNER JOIN order_statuses os ON o.status_id = os.id
             WHERE o.shop_id = @ShopId
               AND o.created_at >= @Today
               AND o.created_at < @Tomorrow
-            GROUP BY os.name";
+            GROUP BY COALESCE(NULLIF(o.payment_method, ''), 'unknown')";
 
         var paymentBreakdown = (await _connection.QueryAsync<PaymentBreakdownDto>(paymentSql, parameters, commandTimeout: 5)).AsList();