How to run Predictor on Windows without NCCL support?

Hi Team,

Thank you for your work. Currently I am trying to run [video predictor notebook](https://github.com/facebookresearch/sam3/blob/main/examples/sam3_video_predictor_example.ipynb) and it will raised error. How to choose a backend which support Windows?

At the same time I found that NCCL will support windows in a near future. But this near might take a few months. [nccl roadmap](https://github.com/NVIDIA/nccl/issues/1896)

```
RuntimeError: Distribnuted package doesn't have NCCL built in
```

And my code is:
`predictor = build_sam3_video_predictor(gpus_to_use=gpus_to_use, checkpoint_path=os.path.join(sam3_root, "weights/sam3.pt"))`

Thank you.

Start with examples/sam3_video_predictor_example.ipynb and the build_sam3_video_predictor(...) entry point, then reproduce the reported RuntimeError on Windows. Trace where distributed initialization selects NCCL and determine whether a supported backend can run this predictor; done means a verified Windows-compatible path or a clear documentation of the limitation.

Written by the indexing model from the issue text.