Speed up the Working pulse animation when Fast mode is enabled

What variant of Codex are you using?

CLI

What feature would you like to see?

When Codex is running in Fast mode, I’d like the left-to-right pulse / breathing animation used by the Working status indicator to run faster than it does in normal mode.

Right now, Fast mode changes the execution behavior, but the Working animation appears to keep the same pacing. This makes the UI feel slightly out of sync with the selected mode.

My proposal is to keep the existing visual design and motion direction, but reduce the animation cycle duration when Fast mode is active.

Suggested behavior:
• Normal mode: keep the current animation speed
• Fast mode: use a noticeably faster pulse animation for the Working indicator

This would make Fast mode feel more mode-aware and responsive without requiring any major UI redesign.

Additional information

This is a small UX improvement rather than a functional change. The goal is to better align visual feedback with the meaning of Fast mode.

A faster Working animation in Fast mode could:
• make the mode distinction clearer at a glance
• improve perceived responsiveness
• reinforce that Fast mode is intentionally operating with a different pacing profile