Handle exception caused by context window overflow in Canvas AI

Overview

While working on #3547209: Provide Canvas patterns as 'component best practices' context to AI, we attempted to handle exceptions that occur when the pattern context exceeds the context window limit. We attempted to address this within a tool and instruct the Agent to consider only the most relevant portion of the context, rather than the entire context. However, this approach did not work.

Proposed resolution

TBD

User interface changes