fix(OOM): cap GPU blocks at 5000 via BI100_MAX_GPU_BLOCKS env var

Profiling zeros-out attention → vllm overestimates free memory → 7942 blocks
→ first real request OOMs. Cap at 5000 (80K tokens / 16 block_size).

patch_block_major_worker_capacity.py reads BI100_MAX_GPU_BLOCKS from env,
caps num_gpu_blocks after reserve_block_major_gpu_blocks.

computility-run.yaml

@@ -49,3 +49,5 @@ env:
       value: '1'
     - name: PYTORCH_CUDA_ALLOC_CONF
       value: max_split_size_mb:512
+    - name: BI100_MAX_GPU_BLOCKS
+      value: '5000'