Add a Toggle Rich Preview command and configurable shortcut

What variant of Codex are you using?

Codex App 26.707.41301 (build 5103) on macOS 26.5.2, Apple Silicon.

What feature would you like to see?

Please add a registered Toggle Rich Preview command for the Review and file-diff views, and expose it in both the Command Menu and Settings → Keyboard Shortcuts.

When reviewing Markdown changes, I frequently switch between:

• the raw diff, to inspect exact source changes; and
• the rendered Markdown preview, to read the resulting document.

Today, this requires opening the Review options dropdown and clicking Enable rich preview or Disable rich preview every time. That interrupts a keyboard-driven review workflow.

Acceptance criteria:

• One command toggles Rich Preview for the currently viewed Markdown diff.
• The command appears in the Command Menu.
• The command appears in Keyboard Shortcuts and can be assigned a custom shortcut.
• The command state and the existing Enable/Disable rich preview menu item remain synchronized.
• A default shortcut is optional; exposing a bindable command is the important part.

Additional information

This is especially useful for documentation-heavy reviews, where both the rendered result and exact Markdown source changes need to be checked repeatedly. The current workaround is to reopen the Review options menu for every switch.