Address issue #249: Windows AMD ROCm torch.distributed.ReduceOp compatibility
Technical implementation:
- Add patch_torch_distributed_reduceop() to PyTorchPatches class
- Create stub ReduceOp class when missing from torch.distributed
- Inject stub early in startup before engine imports
- Enables single-GPU inference on Windows AMD ROCm 7.2 builds
This allows bundled engines (Step Audio EditX, Higgs Audio, IndexTTS, etc.) to import successfully even when PyTorch 2.9.1+rocmsdk20260116 has incomplete torch.distributed module.