## Summary

Inline code in rendered markdown previously used only the default
foreground color with a subtle background tint, which made it visually
indistinguishable from surrounding prose in some themes.

This change looks up the `text.literal` syntax style from the active
theme and applies its color to inline code, matching the treatment used
for inline code elsewhere in the editor (e.g. syntax highlighting in
source buffers). When the theme does not define `text.literal`, the
color falls back to the previous default.


Self-Review Checklist:

- [x] I've reviewed my own diff for quality, security, and reliability
- [x] Unsafe blocks (if any) have justifying comments
- [x] The content is consistent with the [UI/UX
checklist](https://github.com/zed-industries/zed/blob/main/CONTRIBUTING.md#uiux-checklist)
- [x] Tests cover the new/changed behavior
- [x] Performance impact has been considered and is acceptable

Release Notes:

- Improved inline code in rendered markdown to use the theme's
`text.literal` syntax color