v2.1.166

Version 2.1.166 of the Claude API introduces several enhancements, including a `fallbackModel` setting that allows for up to three fallback models to be used in case the primary model is unavailable. It also adds glob pattern support for deny rules, hardens cross-session messaging security, and improves error handling for API requests. These updates are crucial for developers as they enhance reliability, control, and security in deploying AI applications with the Claude framework.