feat: LaTeX rendering

What variant of Codex are you using?

CLI

What feature would you like to see?

Proposal: render LaTeX in the Codex TUI

<img width="1853" height="1375" alt="Image" src="https://github.com/user-attachments/assets/5d5c1638-fa03-4543-b5ee-b4815e32fc8d" />

Background

LaTeX rendering has been requested previously. I recently shared a prototype on twitter, which was positively received, and @fcoury invited me to contribute it.

I cannot open a PR as it is restricted to collaborators, however my implementation can be found here:

https://github.com/haskallcurry/codex/tree/feat/kitty-latex-ratex

Implementation

The implementation:

• recognizes explicitly delimited display and inline math while excluding Markdown code;
• renders it in-process using RaTeX, a Rust implementation of KaTeX-style mathematical layout;
• displays the resulting images using the Kitty graphics protocol, similar to the existing /pets feature;
• does not require an external TeX installation or renderer process.

Using KaTeX directly would require an HTML/CSS layout and rasterization engine.

Known limitations

• Inline images must fit terminal-cell geometry, and their baseline alignment varies somewhat between terminal implementations. Inline math is therefore rendered in Unicode whenever possible.
• Native terminal selection copies the Kitty Unicode-placeholder cells rather than the original LaTeX source.

Additional information

_No response_