Add a button to remove the plan UI (#52360)

## Context

This PR adds a button to remove the plan UI, if the user wants.

## Self-Review Checklist

<!-- Check before requesting review: -->
- [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:

- N/A
b95542410cMikayla Maki committed on 3/25/2026, 4:01:15 PM· committed by GitHubparent6aaf08d
2 files changedLine totals unavailable