SGLang 0.5.18 MiniMax-H3 benchmark compatibility patch

The stock 0.5.18 request contract accepts only short_edge=768. The Base benchmark in this repository used a narrowly scoped compatibility patch for four 16:9 canvases. The patched copies here reproduce the same mapping in the isolated sglang-lora environment:

requested short edge resolved canvas
480 864×480
720 1280×736
768 1344×768 (stock policy)
1080 1920×1088

Only the three non-stock short edges are restricted to 16:9. upstream-0.5.18 contains the untouched files retrieved before installation; patched-0.5.18 contains the benchmark-compatible copies. This patch changes request/shape validation only; it does not alter model kernels, LoRA weights, scheduling, or sampling.