Introducing Exa 2.0

Introduced Exa 2.0 with three major updates: Exa Fast (sub-350ms P50 latency), Exa Auto (improved quality), and Exa Deep (agentic, high-quality search). Detailed the technical underpinnings including a larger index, new embedding model training on a 144x H200 cluster, and vector database optimizations (clustering algorithms, lexical compression, assembly optimizations in Rust). Outlined latency and search quality evaluation methods, including new benchmarks and RAG evaluation harnesses.