int8 always load from disk

bernini int8 , start with -disable-pinned-memory --reserve-vram 0.5. ram is cleared after executing,very strange

python 313tor212cu130

### Debug Logs

```powershell
[INFO] got prompt
[INFO] Model WanTEModel prepared for dynamic VRAM loading. 6419MB Staged. 0 patches attached. Force pre-loaded 73 weights: 488 KB.
[INFO] 0 models unloaded.
[INFO] Model WanVAE prepared for dynamic VRAM loading. 241MB Staged. 0 patches attached. Force pre-loaded 60 weights: 61 KB.
[INFO] 0 models unloaded.
[INFO] Model WanVAE prepared for dynamic VRAM loading. 241MB Staged. 0 patches attached. Force pre-loaded 60 weights: 61 KB.
[INFO] 0 models unloaded.
[INFO] Model WanVAE prepared for dynamic VRAM loading. 241MB Staged. 0 patches attached. Force pre-loaded 60 weights: 61 KB.
[INFO] 0 models unloaded.
[INFO] Model WanVAE prepared for dynamic VRAM loading. 241MB Staged. 0 patches attached. Force pre-loaded 60 weights: 61 KB.
[INFO] 0 models unloaded.
[INFO] Model WAN21 prepared for dynamic VRAM loading. 13858MB Staged. 893 patches attached. Force pre-loaded 160 weights: 1603 KB.
100%|████████████████████████████████████████████████████████████████████████████████████| 2/2 [00:34<00:00, 17.41s/it]
[INFO] Model WAN21 prepared for dynamic VRAM loading. 13858MB Staged. 893 patches attached. Force pre-loaded 160 weights: 1603 KB.
100%|████████████████████████████████████████████████████████████████████████████████████| 2/2 [00:34<00:00, 17.45s/it]
[INFO] Model WanVAE prepared for dynamic VRAM loading. 241MB Staged. 0 patches attached. Force pre-loaded 60 weights: 61 KB.
[INFO] Prompt executed in 93.43 seconds
```

Reproduce the report with the bernini int8 model, -disable-pinned-memory, and --reserve-vram 0.5, using the provided debug-log pattern as the baseline. Trace the model-loading path responsible for the repeated dynamic-VRAM messages and confirm whether int8 weights are loaded from disk and whether RAM is released after execution; done means the behavior is explained and a focused regression check covers it.

Written by the indexing model from the issue text.