Excessive Memory Overcommit on High-RAM Systems

ComfyUI commits significantly more virtual memory than it actually uses on high-RAM systems. This forces users to maintain unnecessarily large pagefiles and can cause OOM crashes despite abundant available physical memory.

With a 20GB pagefile (80GB total virtual memory), ComfyUI uses 45GB actual memory but commits 75GB virtual memory. The application will crash with OOM errors when committed memory hits 80GB/80GB, even though there's still ~30GB of RAM available to use. It's committing 67% more memory than it needs, it's asking for almost twice as much memory as it actually uses.

It looks like around model_management.py:598, there appears to be a 10% safety margin built in, which on a 64GB system should only add ~6GB (or maybe 8GB if calculated against total virtual memory including pagefile). However, the actual overcommit is 30GB - which represents 46% of my total physical RAM. This suggests percentage-based allocation doesn't scale appropriately for high-memory systems.

Edit: specifically I'm seeing this allocation with Wan native comfyui flow.

### Expected Behavior

More RAM should reduce memory pressure and overcommit

### Actual Behavior

RAM leads to proportionally larger overcommit (67% waste on 64GB system)

### System

[ComfyUI 0.3.35](https://github.com/comfyanonymous/ComfyUI)
[ComfyUI_frontend v1.20.4](https://github.com/Comfy-Org/ComfyUI_frontend)
RAM: 64GB (62GB usable after iGPU allocation)
GPU: RTX 3090 24GB VRAM
OS: Windows 11