Fix AgentName

src/Managing.Application.Abstractions/Repositories/IUserRepository.cs

@@ -4,7 +4,7 @@ namespace Managing.Application.Abstractions.Repositories;
 
 public interface IUserRepository
 {
-    Task<User> GetUserByAgentNameAsync(string agentName);
+    Task<User?> GetUserByAgentNameAsync(string agentName);
     Task<User> GetUserByNameAsync(string name, bool fetchAccounts = false);
     Task<IEnumerable<User>> GetAllUsersAsync();
     Task SaveOrUpdateUserAsync(User user);