eval: Improve `StreamingEditFileTool` performance (#52428)

## Context

| Eval | Score |
|------|-------|
| eval_delete_function | 1.00 |
| eval_extract_handle_command_output | 0.96 |
| eval_translate_doc_comments | 0.96 |

Porting the rest of the evals is still a todo.

## 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

---------

Co-authored-by: Ben Brandt <benjamin.j.brandt@gmail.com>
dd0d87f4eeBennet Bo Fenner committed on 3/26/2026, 1:53:49 PM· committed by GitHubparent12bdc20
4 files changedLine totals unavailable