nvvfx bundled libcudnn.so.9 (9.7.1 shim, no sub-libraries) is loaded RTLD_GLOBAL and aborts any later cuDNN consumer (onnxruntime / DWPose) — same class as #34

## Symptom

With this node pack installed, any custom node that binds to cuDNN **after** ComfyUI startup crashes the whole process. First victim here: `comfyui_controlnet_aux` DWPose, whose onnxruntime CUDA session is created lazily on first use:

```
DWPose: Caching ONNXRuntime session yolox_l.onnx...
Unable to load any of {libcudnn_ops.so.9.7.1, libcudnn_ops.so.9.7, libcudnn_ops.so.9, libcudnn_ops.so}
Invalid handle. Cannot load symbol cudnnCreateFilterDescriptor
Fatal Python error: Aborted
```

ComfyUI dies (SIGABRT), the in-memory history is lost. Note the version in the message: **9.7.1** is neither the cuDNN torch ships (9.19 / 9.20) nor anything else in the venv. It is the version of the shim that ends up being called.

## Root cause

`nvvfx/_lib_loader.py` (nvidia-vfx 0.1.0.1) does, at import time:

```python
for lib_name in _LINUX_LIBS: # includes "libcudnn.so.9"
ctypes.CDLL(str(lib_path), mode=ctypes.RTLD_GLOBAL)
```

`nvvfx/libs/libcudnn.so.9` is a cuDNN 9.7.1 **shim** (125 KB) shipped **without** its sub-libraries (`libcudnn_ops`, `libcudnn_graph`, ...). Torch loads its own cuDNN with `RTLD_LOCAL`, so it is not in the global symbol scope. Anything loaded after `import nvvfx` (onnxruntime's CUDA provider, or any other cuDNN user) resolves `cudnnCreate*` through the global scope, hits the 9.7.1 shim, which then tries to dlopen `libcudnn_ops.so.9.7.1`, fails, and aborts.

This is the same mechanism as #34 (bundled `libnvinfer.so.10` 10.9.0 loaded first, breaking TensorRT 10.12 builders), with cuDNN instead of TensorRT.

## Minimal reproduction (outside ComfyUI)

```python
import torch, onnxruntime as ort # OK: CUDAExecutionProvider session works
import torch, nvvfx, onnxruntime as ort # abort on ort.InferenceSession(..., providers=["CUDAExecutionProvider"])
```

Environment: Ubuntu, RTX 5060 Ti, torch 2.12.0+cu132 (nvidia-cudnn-cu13 9.20), onnxruntime-gpu 1.24.4, nvidia-vfx 0.1.0.1, ComfyUI v0.34, this pack at 892515e.

## Workaround that works

Removing the bundled shim makes the VFX libraries resolve `libcudnn.so.9` against the cuDNN already loaded by torch:

```
mv site-packages/nvvfx/libs/libcudnn.so.9 site-packages/nvvfx/libs/libcudnn.so.9.disabled
```

Verified after that: onnxruntime CUDA sessions work, DWPose works, and `RTXVideoSuperResolution` still runs fine on the torch cuDNN (full VSR runs, 1080p, ULTRA).

## Suggested fix

Either do not bundle `libcudnn.so.9` in the `nvidia-vfx` wheel (torch always provides one), or ship the complete cuDNN (shim + sub-libraries), or load the bundled libraries without `RTLD_GLOBAL` so they cannot shadow the environment's own cuDNN / TensorRT for other nodes. I understand the wheel is NVIDIA's rather than this repo's, but this repo is where users hit it.

Start with nvvfx/_lib_loader.py and the bundled nvvfx/libs/libcudnn.so.9; reproduce the import-order failure using the minimal torch/onnxruntime/nvvfx example. Compare the loading behavior with #34 and verify a fix by confirming ONNXRuntime CUDA sessions and DWPose work without breaking RTXVideoSuperResolution.

Written by the indexing model from the issue text.