fix: wire up admin attendance page to real API, add BFF shop attendance endpoint

- BFF: add GET /api/bff/shops/{shopId}/attendance proxy to merchant-service
- ShopAttendance.razor: replace mock data with real attendance API call
- Calculate present/late/absent counts from actual attendance records

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

apps/web-client-tpos-net/src/WebClientTpos.Client/Pages/Admin/Shop/ShopAttendance.razor

@@ -124,10 +124,17 @@
             {
                 var staff = await DataService.GetStaffForShopAsync(shopGuid);
                 _staffCount = staff.Count;
-                // EN: Mock attendance for now — will proxy to real API
-                // VI: Mock chấm công tạm thời — sẽ proxy đến API thực
-                _records = new();
-                _presentToday = staff.Count;
+
+                // EN: Load real attendance data from merchant-service via BFF.
+                // VI: Tải dữ liệu chấm công thực từ merchant-service qua BFF.
+                var attendance = await DataService.GetListFromApiAsync<AttendanceRow>(
+                    $"api/bff/shops/{shopGuid}/attendance?month={_month}&year={_year}");
+                _records = attendance;
+
+                var today = DateTime.UtcNow.Date;
+                _presentToday = attendance.Count(a => a.Date.Date == today);
+                _lateCount = attendance.Count(a => a.Date.Date == today && a.CheckIn.HasValue && a.CheckIn.Value.Hour >= 9);
+                _absentCount = _staffCount - _presentToday;
             }
         }
         catch { }

apps/web-client-tpos-net/src/WebClientTpos.Server/Controllers/StaffController.cs

@@ -414,6 +414,17 @@ public class StaffController : ControllerBase
         return await _merchant.PostAsJsonAsync("/api/v1/attendance/check-out", payload).ProxyAsync();
     }
 
+    /// <summary>
+    /// EN: Get attendance records for a shop (admin) — proxies to merchant-service.
+    /// VI: Lấy bản ghi chấm công theo shop (admin) — proxy đến merchant-service.
+    /// </summary>
+    [HttpGet("shops/{shopId:guid}/attendance")]
+    public Task<IActionResult> GetShopAttendance(Guid shopId, [FromQuery] int month = 0, [FromQuery] int year = 0)
+    {
+        var qs = $"?month={month}&year={year}";
+        return _merchant.GetAsync($"/api/v1/attendance/shop/{shopId}{qs}").ProxyAsync();
+    }
+
     /// <summary>
     /// EN: Get all available staff roles.
     /// VI: Lấy tất cả vai trò nhân viên hiện có.