fix(superadmin): add shops list to merchant detail view

- Add AdminShopSummaryDto to AdminDtos.cs
- Add Shops list to AdminMerchantDetailDto (optional, with default null)
- Fetch shops in GetMerchantDetailQueryHandler with status + category name joins
- Tab "Cửa hàng" now shows real shop data (name, category, status, created date)

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

services/merchant-service-net/src/MerchantService.API/Application/Queries/Admin/AdminDtos.cs

@@ -78,7 +78,15 @@ public record AdminMerchantDetailDto(
     DateTime CreatedAt,
     DateTime? UpdatedAt,
     DateTime? VerifiedAt,
-    Guid? VerifiedBy);
+    Guid? VerifiedBy,
+    List<AdminShopSummaryDto>? Shops = null);
+
+/// <summary>
+/// EN: Shop summary for merchant detail view.
+/// VI: Tóm tắt cửa hàng cho trang chi tiết merchant.
+/// </summary>
+public record AdminShopSummaryDto(
+    Guid Id, string Name, string? Category, string? Status, DateTime CreatedAt);
 
 #endregion
 

services/merchant-service-net/src/MerchantService.API/Application/Queries/Admin/GetMerchantDetailQuery.cs

@@ -4,6 +4,7 @@
 using MediatR;
 using Microsoft.EntityFrameworkCore;
 using MerchantService.Domain.AggregatesModel.MerchantAggregate;
+using MerchantService.Domain.AggregatesModel.ShopAggregate;
 using MerchantService.Domain.Exceptions;
 using MerchantService.Infrastructure;
 
@@ -54,10 +55,21 @@ public class GetMerchantDetailQueryHandler : IRequestHandler<GetMerchantDetailQu
             .FirstOrDefaultAsync(cancellationToken)
             ?? throw new DomainException($"Merchant {request.MerchantId} not found");
 
-        var shopsCount = await _context.Shops
+        // EN: Fetch shops for this merchant with status names
+        // VI: Lấy danh sách shops của merchant với tên status
+        var shops = await _context.Shops
+            .AsNoTracking()
             .Where(s => EF.Property<Guid>(s, "_merchantId") == request.MerchantId
                      && !EF.Property<bool>(s, "_isDeleted"))
-            .CountAsync(cancellationToken);
+            .Join(_context.Set<ShopStatus>(), s => s.StatusId, st => st.Id, (s, st) => new { s, StatusName = st.Name })
+            .Join(_context.Set<BusinessCategory>(), x => x.s.CategoryId, c => c.Id, (x, c) => new { x.s, x.StatusName, CategoryName = c.Name })
+            .Select(x => new AdminShopSummaryDto(
+                x.s.Id,
+                EF.Property<string>(x.s, "_name"),
+                x.CategoryName,
+                x.StatusName,
+                EF.Property<DateTime>(x.s, "_createdAt")))
+            .ToListAsync(cancellationToken);
 
         var staffCount = await _context.MerchantStaff
             .CountAsync(s => s.MerchantId == request.MerchantId, cancellationToken);
@@ -69,15 +81,16 @@ public class GetMerchantDetailQueryHandler : IRequestHandler<GetMerchantDetailQu
             raw.TypeName,
             raw.StatusName,
             raw.VerifName,
-            null, // BusinessInfo — owned type not easily joined, skip for now
-            null, // SettlementConfig — same
-            shopsCount,
+            null, // BusinessInfo
+            null, // SettlementConfig
+            shops.Count,
             staffCount,
             raw.PlanId,
             PlanNames.ElementAtOrDefault(raw.PlanId) ?? "Starter",
             raw.CreatedAt,
             raw.UpdatedAt,
             raw.VerifiedAt,
-            raw.VerifiedBy);
+            raw.VerifiedBy,
+            shops);
     }
 }