git_ui: make git graph columns toggleable (#59850)

# Objective

TODO

## Solution

TODO

## Self-Review Checklist:

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

## Showcase


https://github.com/user-attachments/assets/ae1e2759-2ae9-4c6f-aba3-b6b557c673bc

---

cc @Anthony-Eid 

Release Notes:

- Git graph: Make columns toggleable

---------

Co-authored-by: Anthony <anthony@zed.dev>
Co-authored-by: Anthony Eid <hello@anthonyeid.me>
fcd0f76952Remco Smits committed on 7/7/2026, 8:01:05 AM· committed by GitHubparenta956add
6 files changedLine totals unavailable