Codex Desktop: closing a full-screen document can leave a blank window

[hacksurvivor]

Summary

In Codex Desktop, closing a document while it is opened full screen can leave the app in a mostly blank black window with no visible document content or useful recovery state.

Repro steps

1. Open a document in Codex Desktop.
2. Open the document in full-screen mode.
3. Close the document using the close button on the document/tab control.
4. Observe that Codex can return to a blank window instead of the previous workspace/thread/document state.

Expected behavior

Closing the full-screen document should cleanly return to the previous Codex workspace/thread or close only the document view without leaving the app blank.

Actual behavior

The app can show a mostly blank black window. The window frame is still visible, but the document content and normal Codex UI are gone.

Evidence

Reported from Codex Desktop on macOS. Screenshots from the user show:

• A large blank black Codex window after closing the full-screen document.
• The close control on the document/tab, labeled with a document named Horus_AI_Trading, that appears to trigger the issue when used after full-screening.

I do not have the exact Codex version from the user's app yet. The issue appears distinct from other blank-window reports tied to auth/startup because this one is triggered by a document full-screen close flow.