After latest update, LTX image generation crashing

### 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

Completes generation.

### Actual Behavior

Fails with error. This was working until I upgraded.

### Steps to Reproduce

LTX image2video generation

### Debug Logs

```powershell
[INFO] got prompt
[INFO] VAE load device: cuda:0, offload device: cpu, dtype: torch.float32
[INFO] model weight dtype torch.bfloat16, manual cast: None
[INFO] model_type FLUX
[INFO] VAE load device: cuda:0, offload device: cpu, dtype: torch.bfloat16
[WARNING] no CLIP/text encoder weights in checkpoint, the text encoder model will not be loaded.
[INFO] Requested to load VideoVAE
[INFO] Model VideoVAE prepared for dynamic VRAM loading. 1384MB Staged. 0 patches attached.
[INFO] Found quantization metadata version 1
[INFO] Using MixedPrecisionOps for text encoder
[INFO] CLIP/text encoder model load device: cuda:0, offload device: cpu, current: cpu, dtype: torch.float16
[INFO] Requested to load LTXAVTEModel_
[INFO] Model LTXAVTEModel_ prepared for dynamic VRAM loading. 11200MB Staged. 0 patches attached. Force pre-loaded 400 weights: 1749 KB.
[INFO] Model LTXAVTEModel_ prepared for dynamic VRAM loading. 11200MB Staged. 0 patches attached. Force pre-loaded 400 weights: 1749 KB.
[INFO] Requested to load LTXAV
[INFO] Model LTXAV prepared for dynamic VRAM loading. 40050MB Staged. 0 patches attached. Force pre-loaded 608 weights: 3303 KB.
0%| | 0/8 [00:26

Start by reproducing the LTX image2video workflow after the upgrade, then trace the reported failure through comfy/ldm/lightricks/av_model.py, comfy/model_prefetch.py, and comfy/ops.py. Compare the failing execution with the last working version and use the traceback's hostbuf_file_reader_read failure to narrow the regression. Done means the same workflow completes generation without this exception.

Written by the indexing model from the issue text.