[agent] macOS: scrolling is unusably choppy on battery, smooth on AC power

[agent] Reporting observed desktop-app behavior at the user's request.

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

26.901.41123 (7942), verified from the installed application's Info.plist.

What subscription do you have?

Not provided in this report.

What platform is your computer?

macOS 26.5.2, Apple M4 MacBook Air, built-in display.

What issue are you seeing?

Scrolling in the desktop app is severely choppy on battery power. The user describes it as
feeling like approximately 15 fps; this is a subjective estimate, not a measured frame rate.
Plugging the laptop into AC power immediately makes scrolling feel smooth.

The user also reports that macOS lists Codex as "using significant energy." The scrolling
causes discomfort and makes the desktop app unusable for this user on battery, driving them
back to the CLI. Please prioritize rendering efficiency and usable scrolling on battery power.

What steps can reproduce the bug?

Observed on the machine above:

1. Use the Codex desktop app on battery power and scroll through a conversation.
2. Observe severely choppy scrolling.
3. Plug the laptop into AC power and scroll again.
4. Scrolling becomes smooth without changing the conversation or appearance settings.

What is the expected behavior?

Conversation scrolling should remain smooth on battery power, with efficient CPU/GPU use.
Connecting AC power should not be necessary for a comfortable reading experience.

Additional information

• macOS Low Power Mode is disabled for both battery and AC power, verified with pmset.
• Enabling Reduce motion did not help; the user felt it might have made things worse.
• Disabling Translucent sidebar did not help.
• No frame-time trace or GPU utilization measurement has been captured, and the root cause
  has not been established.
• Related efficiency report: #16857. This report concerns a distinct observed trigger:
  scrolling is choppy on battery and becomes smooth immediately when AC is connected.

Co-Authored-By: Codex noreply@openai.com

No source file, test, or entry point is identified. First reproduce scrolling on the specified M4 MacBook Air while switching between battery and AC power, then capture the missing frame-time, GPU, and energy measurements. Done means scrolling is smooth and usable on battery without requiring AC power.