Fix “Open file in project" option in the right-click menu not working (#60807)

# Objective

Fix file header context menu actions in multi-file Git history diffs.
Previously, `Open File in Project` worked for the first file but did
nothing for subsequent files.

Fixes #60790

## Solution

Include the buffer ID in each file header context menu's GPUI element
ID. This prevents multiple file headers in split diff views from sharing
the same menu state.

## Testing

- Ran `cargo check -p editor --lib`.
- Ran `cargo fmt --package editor -- --check`.
- Reviewers can test by opening a multi-file commit from Git Panel →
History in split diff mode, then using `Open File in Project` on the
second and subsequent file headers.


https://github.com/user-attachments/assets/46fa4e15-60ac-4ae3-9a73-a89c7f107cb0

## 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 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
- [x] Performance impact has been considered and is acceptable

---

Release Notes:

- Fixed opening project files from context menus in multi-file Git
history diffs.

Co-authored-by: peakxy <2465549609@qq.com>
08359123acYifeng Xu committed on 7/12/2026, 9:08:20 PM· committed by GitHubparent60099a0
1 file changedLine totals unavailable