Update benchmark results: Milvus 2.6.14, ElasticCloud 8.17, ZillizCloud

Milvus results (16c64g, force_merge, v2.6.14):
- 1M Cohere: SQ4U+FP16 (sweep refine_k) + SQ8 (sweep ef), 8 points each
- 10M Cohere: SQ4U+FP16 + SQ8 (sweep ef), 8 points each
- Total 32 benchmark configurations

ElasticCloud and ZillizCloud results from standard benchmark runs.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: Ubuntu