[CLI] Add back percentage display for context used in session (the visual meter is not nearly precise enough)

What variant of Codex are you using?

CLI

What feature would you like to see?

Basically what the title says.

I don't know if I miss some setting to change it back to percentage, but the new visual meter for used context in a session is _not good_. I would like to see the exact percentage I have left. Please add at least an alternative statusline widget for the percentage. Thank you very much! 🙏

Additional information

<img width="500" alt="Image" src="https://github.com/user-attachments/assets/72552fae-6e6d-49cf-9cd4-01e24fd3bdb8" />