Incorporate automatic summarization into context window overflow handling

Extend the implementation to automatically trigger summarization when Bedrock's context window limits are exceeded. This involves error detection for specific Bedrock error messages, fallback mechanisms, and updating the conversation handling logic to recover gracefully from overflow errors. The goal is to make the transition seamless when token limits are reached.

Start by tracing the conversation handling logic and the paths that process Bedrock context-window error messages; the payload does not name specific files or tests. Define the required overflow detection and fallback behavior, then verify that conversations recover seamlessly when token limits are exceeded.

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