Extends d79a443 — that commit correctly moves I/O tensors to the weight
matrix's device before L-BFGS optimization, but the captured tensors
remain on their original GPU between trials. When reset_model() reloads
the model, device assignments can change, leaving orphaned tensors on
GPUs that now need that VRAM for the reloaded weights.
Moving to CPU at capture time in get_module_io ensures:
- Zero VRAM wasted on stale device assignments between trials
- Clean CPU→target transfer regardless of how devices shuffle on reload
- No overhead on single-GPU (.cpu() is a no-op when already on CPU,
and .to(device) in ara_abliterate handles the final placement)
