[Bug] Session remains blocked after first cyber safeguard event

**Bug Description**
Possible session contamination matching:
https://github.com/anthropics/claude-code/issues/63751

This is an authorized Purple Team assessment of organization-owned infrastructure.
After the first cyber safeguard event, the session remains blocked.

Request ID:
req_011CeMMcup1mhEanwEsjNKpp

**Environment Info**
- Platform: darwin
- Terminal: Apple_Terminal
- Version: 2.1.241
- Feedback ID: b686d946-47f8-444c-a6e4-22193d0098d9

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

No source file, test, or entry point is identified. Start by reviewing the linked issue and the report associated with request ID req_011CeMMcup1mhEanwEsjNKpp; reproduce the first cyber safeguard event on the stated macOS environment and determine the expected session-unblocking behavior. Done means the session no longer remains blocked after that event, with a regression test covering it.

索引モデルが issue の本文から書いたものです。