When a /responses forwarding loop has attempted an OpenAI passthrough
account, sanitize every subsequent non-passthrough attempt by deriving its
body from the immutable canonical request and dropping provider-specific
encrypted reasoning input items in full.
This prevents Bedrock-compatible accounts from rejecting Kiro reasoning
IDs and encrypted_content, including on same-account retries and later
non-passthrough failovers. Preserve JSON numbers exactly while sanitizing.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
