[BUG] Loss of most of my mods during a file transfer

### Is there an existing issue for this?

- [x] I have searched the existing issues

### Current Behavior

I wanted to move my mods from one folder to another. As far as I understand, moving files involves copying them to the new location and then deleting the originals, which may require having enough free space to temporarily store both copies.

However, the system told me that there was not enough available storage space to complete the operation, yet it still deleted the original files, even though the mods were never successfully transferred to the new folder.

As a result, I lost the vast majority of my mods, including mods that I had paid for.

I honestly have no idea how I am supposed to recover these paid mods or regain access to them.

[log.txt](https://github.com/user-attachments/files/32268250/log.txt)

### Expected Behavior

This is a serious issue: if a file transfer fails, especially due to insufficient storage space, the original files should absolutely not be deleted unless the copy to the destination has been successfully completed and verified.

The system should either:

Check the available storage space before starting the operation;
Complete the copy before deleting any original files;
Or, at the very least, preserve the original files if the transfer fails.

A failed move operation should never result in data loss.

### Steps To Reproduce

_No response_

### Environment

```markdown
- Mod Assistant Version: 5.9.96
- OS: windows 11
- Virtualized: Non
- Steam
```

### Anything else?

_No response_

Start by reviewing the attached log.txt and the file-transfer behavior in Mod Assistant 5.9.96 on Windows 11 with Steam. Establish a reproducible move that fails from insufficient storage, then verify that the original files remain intact whenever the transfer does not complete successfully.

Written by the indexing model from the issue text.