Under the hood
New helper sorts unrecognized API error messages into overloaded, rate_limit, server_error, or other
What
A new pair of functions checks whether a message is an API error that doesn't already match a known, specific error case, and if so, sorts its .error field into one of four buckets: overloaded, rate_limit, server_error, or other.
Why
This gives Claude Code a consistent way to categorize API errors it doesn't have specific handling for, which likely feeds into how errors are logged or reported.