Add webhook

src/Managing.Application/Users/UserService.cs

@@ -165,4 +165,21 @@ public class UserService : IUserService
         await _userRepository.UpdateUser(user);
         return user;
     }
+
+    public async Task<User> UpdateTelegramChannel(User user, string telegramChannel)
+    {
+        // Validate Telegram channel format (must start with @ and contain only allowed characters)
+        if (!string.IsNullOrEmpty(telegramChannel))
+        {
+            string pattern = @"^@[a-zA-Z0-9_]{5,32}$";
+            if (!Regex.IsMatch(telegramChannel, pattern))
+            {
+                throw new Exception("Invalid Telegram channel format. Must start with @ and be 5-32 characters long, containing only letters, numbers, and underscores.");
+            }
+        }
+
+        user.TelegramChannel = telegramChannel;
+        await _userRepository.UpdateUser(user);
+        return user;
+    }
 }