NVIDIA DGX Spark installation fails because hard dependency `nvidia-vfx` has no `linux_aarch64` wheel

ARM64/aarch64 installation fails because hard dependency `nvidia-vfx` has no `linux_aarch64` wheel

# Body

## Summary

I am trying to install `Nvidia_RTX_Nodes_ComfyUI` on Linux ARM64 (`aarch64`), but installation fails because the project has a hard dependency on `nvidia-vfx`, and `nvidia-vfx` currently does not provide a `linux_aarch64` wheel.

From what I can see, this is not a ComfyUI Manager issue. It is a platform compatibility issue caused by the required dependency.

## Environment

- OS: Linux
- Architecture: `aarch64`
- Python: `3.12.3`
- CUDA: `13.0`
- NVIDIA Driver: `580.126`
- ComfyUI: `0.16.1`

## Reproduction

Install the node, or directly run:

```bash
pip install --extra-index-url https://pypi.nvidia.com/ nvidia-vfx
```

## Actual result

Installation fails with:

```text
RuntimeError: Didn't find wheel for nvidia-vfx 0.1.0.1
```

The debug output shows that the package is checking only these wheel targets:

- `cp310 ... manylinux ... x86_64`
- `cp311 ... manylinux ... x86_64`
- `cp312-abi3 ... manylinux ... x86_64`
- Windows `amd64`

There does not appear to be any `linux_aarch64` wheel.

## Additional findings

This repository appears to require `nvidia-vfx` as a hard dependency:

- `requirements.txt` includes `nvidia-vfx`
- `pyproject.toml` includes `nvidia-vfx`
- the node imports `nvvfx` directly at startup

Also, the published `nvidia-vfx` source package is a `wheel-stub` package that downloads a prebuilt wheel from `https://pypi.nvidia.com/`, so this does not look like something users can build locally on ARM from source.

## Expected result

One of the following would help:

1. Provide `linux_aarch64` support for `nvidia-vfx`, if ARM64 is intended to be supported.
2. Explicitly document that `Nvidia_RTX_Nodes_ComfyUI` is currently `x86_64`-only.
3. Fail with a clearer platform error message in the README or installer path.

## Request

Could you confirm whether ARM64/aarch64 support is planned?

If not, please consider documenting that this node currently requires `x86_64` Linux or Windows, so ARM users do not spend time debugging an installation path that cannot succeed.