Fixed a save issue affecting very large/long-running saves.
- Large saves now write to the protected desktop save file before attempting the Local Storage compatibility copy.
- Fixed cases where Save & Exit appeared to work but progress was not actually being saved.
- Improved recovery behavior so desktop saves can load from the main save, backup, or recovery file without unnecessarily copying huge saves back into Local Storage.
- Reduced the chance of oversized saves causing save/load failures or long stalls.