fix(hrms): align employee service with UIND schema

Corrects HRMS field names for employees, departments, and location sites.

src/HikvisionAttendanceManager.App/Services/HrmsEmployeeService.cs

@@ -77,6 +77,10 @@ public sealed class HrmsEmployeeService
         }, cancellationToken);
     }
 
+    public async Task<IReadOnlyList<HrmsEmployee>> GetActiveEmployeesBySiteAsync(long siteId, CancellationToken cancellationToken) =>
+        await QueryEmployeesAsync(EmployeeQuery + " WHERE e.is_active = 1 AND e.location_site_id = @siteId ORDER BY employee_display_name",
+            command => command.Parameters.AddWithValue("@siteId", siteId), cancellationToken);
+
     public async Task<IReadOnlyList<HrmsEmployee>> SearchEmployeesAsync(string query, long? siteId, CancellationToken cancellationToken)
     {
         if (string.IsNullOrWhiteSpace(query)) return [];