Implement bidirectional customer conversations with customer-based grouping and order tagging

LittleShop.Client/Models/CustomerMessage.cs

@@ -0,0 +1,24 @@
+namespace LittleShop.Client.Models;
+
+public class CustomerMessage
+{
+    public Guid Id { get; set; }
+    public Guid CustomerId { get; set; }
+    public long TelegramUserId { get; set; }
+    public string Subject { get; set; } = string.Empty;
+    public string Content { get; set; } = string.Empty;
+    public MessageType Type { get; set; }
+    public bool IsUrgent { get; set; }
+    public string? OrderReference { get; set; }
+    public DateTime CreatedAt { get; set; }
+}
+
+public enum MessageType
+{
+    OrderUpdate = 0,
+    PaymentReminder = 1,
+    ShippingInfo = 2,
+    CustomerService = 3,
+    Marketing = 4,
+    SystemAlert = 5
+}