[Bug] Anthropic API Error: reasoning_extraction failure

**Bug Description**
https://support.claude.com/en/articles/15363606

Details: `[reasoning_extraction]`

Request ID: req_011CeE7jDyRoM6bMWJNKJT4A
Why?

**Environment Info**
- Platform: darwin
- Terminal: iTerm.app
- Version: 2.1.237
- Feedback ID: a3d7fefe-d8e7-4909-8a4d-75c31e003d65

**Errors**
```json
[]
```

Start with the linked Claude support article and the reported reasoning_extraction error, using request ID req_011CeE7jDyRoM6bMWJNKJT4A to investigate the Anthropic API interaction. No source file, entry point, or test is identified in the report; done means reproducing the failure, identifying its cause, and verifying that the error no longer occurs.

索引モデルが issue の本文から書いたものです。