## What
- Add the `--cask` flag to the Homebrew update command for Codex.
## Why
- `brew upgrade codex` alone does not update the cask, so users were not
getting the right upgrade instructions.
## How
- Update `UpdateAction::BrewUpgrade` in `codex-rs/tui/src/updates.rs` to
use `upgrade --cask codex`.
## Testing
- [x] cargo test -p codex-tui
Co-authored-by: Thibault Sottiaux <tibo@openai.com>