Rust Vector Database Rewrite

Pinecone has rewritten its core vector database engine from Python and C++ to Rust to improve performance, memory management, and developer experience. This involved identifying and addressing performance bottlenecks through continuous benchmarking and building an observability layer using OpenTelemetry and OpenMetrics. Performance optimizations focused on leveraging Rust's low-level instruction sets, memory layout control, and efficient async task execution with Tokio and Rayon.