This new parameter allows users to specify the exact percentage of GPU VRAM
to use, overriding the offload-strategy. When specified, the model will:
1. Use up to max-gpu-percent of VRAM
2. Offload remaining weights to CPU RAM (--ram)
3. Overflow to disk (--offload-dir) if RAM exhausted
4. Automatically fallback in 5% steps if OOM occurs

Example usage for RTX 3090 with Qwen3.5-35B-A3B:
  coderai --model Qwen/Qwen3.5-35B-A3B --max-gpu-percent 50 --ram 64

This ensures MoE models with high VRAM requirements during generation
can run without OOM by using CPU RAM as the primary offload target.