Fatal Error on Windows: failed printing to stderr: The pipe is being closed. (os error 232)

### Description
The app crashes with a "Fatal Error (Not Responding)" dialog on Windows. The error originates from the Rust standard library when writing to stderr:

```
failed printing to stderr: The pipe is being closed. (os error 232)
at /rustc/4a4ef493e3a1488c6e321570238084b38948f6db/library/std/src/io/stdio.rs:1165:9
```

### Environment
- OS: Windows (Windows_NT)
- App: GitHub Copilot app
- Latest release at time of report: v0.2.19 (exact running version unconfirmed)

### Expected behavior
The app should handle a closed stderr pipe gracefully instead of crashing with a fatal error.

### Notes
`os error 232` is the Windows `ERROR_NO_DATA` / broken-pipe condition, which suggests the downstream consumer of stderr was closed before the app finished writing. A panic while printing to stderr currently surfaces as a fatal "Not Responding" dialog.