SGLang Cross-Hardware Replay Evidence V2

Follow-up evidence packet with H100 NVL repeatability, H100 NVL/H100 SXM held-out replay, MLX subset control metadata, and shutdown receipts.

• README.md
• comparisons/combined_summary.json
• comparisons/h100nvl_selected_clean_repeat_summary.json
• comparisons/h100nvl_heldout_clean_repeat_summary.json
• comparisons/h100nvl_vs_second_cuda_heldout_summary.json
• gpu_lifecycle/instances-after-destroy.json
• meta/v2_summary.json
• meta/manifest.json
• SHA256SUMS.txt