[Bug] Anthropic API Error: Unexpected session termination on PHI-related code

**Bug Description**
I was flagged because I am working on code that deals with patient data, and I was dropped from 5.1 without een asking or prompting any concerns about security, or where the conversation was going. This is incredibly frustrating. Our entire codebase depends on the context of handling PHI- that is the business of health tech.

**Environment Info**
- Platform: win32
- Terminal: windows-terminal
- Version: 2.1.265
- Feedback ID: 5f3626c3-450e-43b2-af5f-33f82a1f3944

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

Start from the reported environment: Claude Code 2.1.265 on win32 in windows-terminal, and use the Feedback ID 5f3626c3-450e-43b2-af5f-33f82a1f3944 to inspect any available logs. The issue does not name code entry points or tests, so first determine whether the termination is reproducible with PHI-related code context. Done means the session no longer drops unexpectedly, or the user receives a clear handled response instead of abrupt termination.

索引モデルが issue の本文から書いたものです。