Download failed!

### Custom Node Testing

- [ ] I have tried disabling custom nodes and the issue persists (see [how to disable custom nodes](https://docs.comfy.org/troubleshooting/custom-node-issues#step-1%3A-test-with-all-custom-nodes-disabled) if you need help)

### Expected Behavior

The downloader should resume from the last successfully downloaded portion of the file rather than restarting from the beginning.

### Actual Behavior

When downloading large model files through ComfyUI, a temporary network interruption causes the download to fail and restart from the beginning. There appears to be no resume support for partially downloaded files.

This is particularly problematic for large models. I was downloading a 27 GB model, and the download failed multiple times at approximately 30%, 50%, and 90%. Each failure forced the download to start again from 0%.

I'm using the latest version.

### Steps to Reproduce

Start downloading a large model (e.g., 20+ GB).
Allow the download to progress significantly.
Trigger a temporary network interruption or encounter a connection issue.
Observe that the download fails.
Restart the download.

### Debug Logs

```powershell
No logs for downloads, and that is another bad design.
```

### Other

_No response_