Pi Coding Agent adds Mistral prompt caching

Prompt caching is becoming the battleground for agent efficiency, and Pi's provider-native support shows that managing context windows intelligently is no longer optional for developer-first tools. By utilizing session IDs for Mistral prompt caching, the agent ensures session affinity and reduces API latency and costs. Furthermore, upgrading undici mitigates potential security vulnerabilities and resolves timeout issues during streaming, while selective provider entry points allow builders to bundle the CLI without bloating applications with unused transports.