Internal classes cannot be reloaded.

If I am reading the history correctly, it seems like back in 2023 there was a fix to allow reloading internal classes. However, I am receiving "inaccessible due to its protection level" errors whenever I make a change to an internal class:

```
FSR: Error when updating files: 'HUDShipUpgradeButton.cs', System.Exception: Compiler failed to produce the assembly. Output: 'C:\Users\USER\AppData\Local\Temp\c9921ed0d75d4fee849e038c879c696c.SourceCodeCombined.cs(27,206): error CS0122: 'HUDUpgradeButton' is inaccessible due to its protection level

C:\Users\USER\AppData\Local\Temp\c9921ed0d75d4fee849e038c879c696c.SourceCodeCombined.cs(29,17): error CS0122: 'ShipUnitBehaviour' is inaccessible due to its protection level

C:\Users\USER\AppData\Local\Temp\c9921ed0d75d4fee849e038c879c696c.SourceCodeCombined.cs(31,18): error CS0122: 'ShipUnitBehaviour' is inaccessible due to its protection level'
```

Comienza reproduciendo el fallo de recarga de HUDShipUpgradeButton.cs e inspecciona la ruta de FastScriptReload que combina y compila el código fuente modificado. Traza cómo se gestionan las clases internas como HUDUpgradeButton y ShipUnitBehaviour, y verifica después que editar una clase interna se recarga sin errores CS0122 de nivel de protección.

Escrito por el modelo de indexación a partir del texto del issue.