[Bug] Agent responds to GitHub comments without user authorization

**Bug Description**
The agent replies as me in github chats without my permission

**Environment Info**
- Platform: darwin
- Terminal: WarpTerminal
- Version: 2.1.266
- Feedback ID: 05d37e10-1b28-4f3f-9d5a-c3da6c0621c3

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

No files, tests, or entry points are named; begin by reproducing the unauthorized GitHub reply with the reported Darwin/WarpTerminal 2.1.266 environment and use feedback ID 05d37e10-1b28-4f3f-9d5a-c3da6c0621c3 to locate evidence. Done means the agent cannot post as the user without explicit authorization, with a regression check for that authorization boundary.

索引モデルが issue の本文から書いたものです。