bug: non-openai model is not streaming output

What version of Codex is running?

│ ● OpenAI Codex (research preview) v0.1.2504220136 │

Which model were you using?

deepseek-chat

What platform is your computer?

Darwin 24.4.0 arm64 arm

What steps can reproduce the bug?

1、run below command

codex -m deepseek-chat -p deepseek

2、input your content

js 冒泡排序

3、not streaming output just a result to me

<img width="1542" alt="Image" src="https://github.com/user-attachments/assets/78df83b2-72cb-4f7d-904f-a4f3ec6a4a3b" />

What is the expected behavior?

_No response_

What do you see instead?

_No response_

Additional information

_No response_