Message history has incorrect state on second resume.

What version of Codex is running?

0.39.0

Which model were you using?

gpt-5

What platform is your computer?

Darwin 24.6.0 arm64 arm

What steps can reproduce the bug?

1. Send multiple messages.
2. Press Esc twice, then select a middle message (not the first one)
3. Send another message.
4. Press Esc twice again, then select the last message.
5. Only the last message remains in the input editor, and the previously shown (duplicated) message disappears.

Video:

https://github.com/user-attachments/assets/caee091d-cdd5-415d-ab59-22e4a59cd8d3

What is the expected behavior?

_No response_

What do you see instead?

_No response_

Additional information

_No response_