Add Alt/Option+P shortcut to open the model picker

Feature request

Add Alt+P (Option+P on macOS) as a keyboard shortcut for opening the existing model picker in the TUI.

Motivation

Switching models is a frequent action, but currently requires opening the slash-command flow. A dedicated shortcut would make model switching faster while reusing the existing picker and behavior.

Expected behavior

• Alt+P / Option+P opens the existing model picker.
• Any unfinished composer draft is preserved, including during an active turn.
• Existing popup focus and startup checks remain respected.
• The shortcut cannot be shadowed by a conflicting custom key binding.

Tested implementation

A focused implementation is available in my public fork:

https://github.com/openai/codex/compare/main...cathrynlavery:codex:feat/alt-p-model-picker?expand=1

The implementation changes five TUI files and includes shortcut routing, draft-preservation coverage, popup/startup guard coverage, and keymap conflict validation.

Validation

• 4,595 TUI tests passed; 6 skipped.
• Formatting and whitespace checks passed.

If this behavior and approach align with the project, would a maintainer be willing to invite this contribution as a pull request?

Implemented with assistance from Knox, an AI assistant.

Start in the TUI shortcut routing and keymap handling, then trace the existing model picker opened by the slash-command flow. Compare the public fork's five-file implementation and its shortcut, draft-preservation, popup/startup guard, and keymap conflict tests. Done means Alt+P or Option+P opens the picker while preserving drafts and respecting existing guards and bindings.