Codex VS Code extension injects empty image_url blocks into some chats, causing permanent 400 errors. #4132

What version of Codex is running?

0.4.14

Which model were you using?

gpt-5-codex

What platform is your computer?

Darwin 25.0.0 arm64 arm

What steps can reproduce the bug?

1. use Codex extension in VS Code (MAc, version 0.4.14)
2. Work in chat normally
3. After some time, any new message (even plain text) fails with:
   stream error: unexpected status 400 Bad Request:
   { "error": { "message": "Invalid 'input[...].content[...].image_url'. Expected a base64-encoded data URL …" } }

Starting new chat works fine.

What is the expected behavior?

Plain text messages should not include image_url

What do you see instead?

Old chat thread carries a ghost image_url attachment, making it unusable.

Additional information

No response