Add project files.

Models/User.cs

@@ -0,0 +1,22 @@
+using System.ComponentModel.DataAnnotations;
+
+namespace LogisticsApp.Server.Models
+{
+    public class User
+    {
+        [Key]
+        public int Id { get; set; }
+
+        [Required]
+        [StringLength(50)]
+        public string Username { get; set; } = string.Empty;
+
+        [Required]
+        public string PasswordHash { get; set; } = string.Empty;
+
+        [Required]
+        public string Role { get; set; } = "admin"; // admin, user
+
+        public DateTime CreatedAt { get; set; } = DateTime.UtcNow;
+    }
+}