fix: Incorrect class_ptr handling in C# layer

[ELDment]

When building a class in the C# layer, class_ptr would consistently receive an incorrect value, experience erroneous pointer dereferencing, or fail to update the class_name

https://discord.com/channels/1178027657594687608/1260707376923672577/1410251539347673289

[nicedayzhu]

Confirmed Pass!

Test code:

public Classes.CPlantedC4? GetPlantedC4()
 {
     var plantedC4 = Generic.FindEntitiesByClassname("planted_c4");
     if (plantedC4 == null)
     {
         Console.WriteLine($"GetPlantedC4: FindEntitiesByClassname returned null +++ ");
         return null;
     }

     if (plantedC4.Length == 0)
     {
         Console.WriteLine($"GetPlantedC4: No planted_c4 entities found +++ ");
         return null;
     }

     Console.WriteLine($"GetPlantedC4: Found {plantedC4.Length} planted_c4 entities ++++ ");

     var firstC4 = plantedC4.FirstOrDefault();
     if (firstC4 == null)
     {
         Console.WriteLine($"GetPlantedC4: FirstOrDefault returned null +++ ");
         return null;
     }
     // 直接传递 CEntityInstance，让构造函数处理转换
     var tmp = new Classes.CPlantedC4(firstC4);

     if (!tmp.IsValid())
     {
         Console.WriteLine($"tmp is InValid +++ ");
         return null;
     }

     Console.WriteLine($"tmp.TimerLength {tmp.TimerLength} +++ ");
     Console.WriteLine($"tmp.BombSite {tmp.BombSite} +++ ");
     return tmp;
 }

Result:

[skuzzis]

Thanks for correcting this <3