Codex desktop: Jupyter notebook opens read-only with no edit option and disabled run controls

Summary

Opening a Jupyter notebook (.ipynb) in the Codex desktop app leaves it in "Read only" mode with no option to edit. The toolbar shows a play icon and "Run all", plus "Restart kernel", but these controls appear disabled and notebook execution is unavailable.

Steps to reproduce

1. Open an .ipynb file in the Codex desktop app's notebook viewer.
2. Observe the "Read only" indicator in the toolbar.
3. Look for an option to enable editing or run notebook cells.

Actual behavior

• The notebook can be viewed but not edited through the notebook UI.
• No edit option is available to the user.
• "Run all" and "Restart kernel" are visible but appear disabled; the user cannot run the notebook.
• The user reports no kernel error. The supplied toolbar screenshot shows no explanation for the disabled state. Kernel availability and the underlying cause have not been independently verified.

Expected behavior

The notebook should allow editing and execution through its notebook controls. If a prerequisite prevents these actions, the UI should explain why and provide an actionable way to resolve it instead of leaving the notebook read-only with unavailable controls.

Evidence and environment

• Codex desktop app on macOS; exact app version not captured.
• A user-provided screenshot shows "IPYNB · 13 cells", "Read only", and greyed-out "Run all" and "Restart kernel" controls.
• This report is based on the user's observation and screenshot; no independent execution test was performed.

Related issue

#45458 requests broader notebook editing, execution, and rich output support. This bug report focuses on the existing notebook viewer showing read-only mode and unavailable execution controls without an explanation.

Start by reproducing the issue in the Codex desktop app on macOS with an .ipynb file, then inspect the notebook viewer's read-only state and disabled controls. Verify whether editing and execution are intentionally unavailable or blocked by an unreported prerequisite. Done when the notebook can be edited and run, or the UI explains the prerequisite and provides an actionable resolution.