[BUG] Internal browser crashes when accessing Windows Credential Manager during authentication

### Preflight Checklist

- [x] I have searched [existing issues](https://github.com/anthropics/claude-code/issues?q=is%3Aissue%20state%3Aopen%20label%3Abug) and this hasn't been reported yet
- [x] This is a single bug report (please file separate reports for different bugs)
- [x] I am using the latest version of Claude Code

### What's Wrong?

When accessing a website that requires authentication (e.g., Google Ads, GitHub), the internal browser opens a Windows Security dialog asking to choose a credential/passkey. This causes the entire Claude Code application to freeze/crash, and a system recovery dialog appears asking to recover files from the Windows installation.

The issue occurs on Windows 11, likely due to how the sandboxed browser interacts with the Windows Credential Manager. The Windows Security window (Segurança do Windows) appears with a list of saved Google accounts, but the application cannot handle this credential selection properly and freezes.

### What Should Happen?

aThe internal browser should handle Windows Credential Manager authentication gracefully without freezing or crashing the application. Either:
1. The browser should not open the Windows Security dialog and instead handle credentials internally
2. 2. Or the application should properly handle the credential selection window without freezing
3. 3. Alternatively, users could be directed to use an external browser (Chrome) for authenticated sites

### Error Messages/Logs

```shell
Windows 11 Home 10.0.26200
Claude Code latest version
When accessing Google Ads or GitHub in the internal browser, Windows Security dialog appears and the app freezes, eventually prompting a system file recovery dialog.
```

### Steps to Reproduce

a1. Open Claude Code on Windows 11
2. Open the internal browser
3. 3. Navigate to https://google.com and try to access Google Ads, or navigate to https://github.com and try to create an issue
4. 4. When the site attempts to authenticate or access saved credentials, the Windows Security dialog ("Segurança do Windows") appears
5. 5. The dialog shows a list of saved Google accounts to choose from
6. 6. The application freezes at this point
7. 7. After a few moments, a Windows system recovery dialog appears asking to recover files from the installation
Alternative: Try accessing any website that triggers credential selection (Google Ads, GitHub, etc.) and wait for the Windows Security dialog to appear

### Claude Model

Not sure / Multiple models

### Is this a regression?

I don't know

### Last Working Version

_No response_

### Claude Code Version

1.40609.1

### Platform

Anthropic API

### Operating System

Windows

### Terminal/Shell

PowerShell

### Additional Information

_No response_

Start by reproducing the crash from the internal browser on Windows 11 using Google Ads or GitHub, then observe the Windows Security credential-selection dialog and the resulting freeze. The issue does not name source files or tests. Done means authentication no longer freezes or crashes Claude Code when Windows Credential Manager requests credential selection.

索引モデルが issue の本文から書いたものです。