chore: some refactors

JOBot.Backend/DAL/Models/User.cs

@@ -13,4 +13,6 @@ public class User
     [MaxLength(50)]
     public string? Username { get; set; }
     public DateTime CreatedAt { get; set; } = DateTime.UtcNow;
+    
+    public string? HeadHunterResumeUrl { get; set; }
 }

JOBot.Backend/Services/gRPC/UserService.cs

@@ -33,4 +33,11 @@ public class UserService(AppDbContext dbContext) : User.UserBase
             Success = false
         });
     }
+
+    public override Task<GetUserResponse> GetUser(
+        GetUserRequest request, 
+        ServerCallContext context)
+    {
+        return null;
+    }
 }