Using option + backspace crashes the app

What version of Codex is running?

0.39

Which model were you using?

gpt-5-codex

What platform is your computer?

Darwin 24.6.0 arm64 arm

What steps can reproduce the bug?

I use iTerm for codex. Today I was able to crash the app, while trying to delete the message that I wrote.
I did that by using option + backspace to delete the message as fast as possible. The result was:

The application panicked (crashed).
Message: assertion failed: self.is_char_boundary(n)
Location: tui/src/bottom_pane/textarea.rs:97

Backtrace omitted. Run with RUST_BACKTRACE=1 environment variable to display it.
Run with RUST_BACKTRACE=full to include source snippets.

What is the expected behavior?

I should be able to delete what I wrote

What do you see instead?

_No response_

Additional information

_No response_