Title: Shift+Tab keybinding conflicts with macOS native focus navigation

What version of the Codex App are you using (From “About Codex” dialog)?

1

What subscription do you have?

1

What platform is your computer?

No response

What issue are you seeing?

Description:
The default Shift+Tab keybinding for composer.togglePlanMode doesn't work in the input box because macOS intercepts it for backward focus navigation.
Steps to reproduce:

1. Focus the input box in Codex desktop app
2. Press Shift+Tab
3. Focus jumps to the element above (e.g., Hooks panel) instead of toggling Plan mode
   Expected behavior:
   Shift+Tab should toggle Plan mode when the input box is focused (like Cursor does by preventing default focus behavior).
   Suggestion:

• Prevent default Shift+Tab focus behavior when input box is focused
• Or change default keybinding to avoid conflict (e.g., Cmd+Shift+M)
• Or add UI for customizing keybindings instead of editing keybindings.json manually
  Environment:
• Codex desktop app (ChatGPT.app)
• macOS

What steps can reproduce the bug?

1

What is the expected behavior?

No response

Additional information

No response

Start by reproducing the issue in the Codex desktop app on macOS with focus in the input box, then trace the composer.togglePlanMode keybinding handling. Done means Shift+Tab toggles Plan mode from the input box instead of moving focus to the previous element.