[Bug] AsyncIterator reproducible error w/ thinking blocks in agent SDK v0.1.70

Bug Description
i am using the AsyncIterator to claude agent sdk and ALWAYS get this "thoughts blocks modified" error when running a particular prompt workflow. It reproduces every time. This is a hard blocker on agent sdk v0.1.70

Environment Info

• Platform: darwin
• Terminal: tmux
• Version: 2.0.71
• Feedback ID: ce0f910b-0200-4efd-8f3a-cedf658a5396

Errors

API Error: 400 {"type":"error","error":{"type":"invalid_request_error","message":"messa
    ges.1.content.23: `thinking` or `redacted_thinking` blocks in the latest assistant
    message cannot be modified. These blocks must remain as they were in the original
    response."},"request_id":"req_011CWBJBS1qYPwAk6hjpkpmN"}