Store ACP thread metadata (#51657)

Before you mark this PR as ready for review, make sure that you have:
- [x] Added a solid test coverage and/or screenshots from doing manual
testing
- [x] Done a self-review taking into account security and performance
aspects
- [x] Aligned any UI changes with the [UI
checklist](https://github.com/zed-industries/zed/blob/main/CONTRIBUTING.md#uiux-checklist)

Release Notes:

- N/A

---------

Co-authored-by: cameron <cameron.studdstreet@gmail.com>
Co-authored-by: Ben Brandt <benjamin.j.brandt@gmail.com>
015225196dBennet Bo Fenner committed on 3/16/2026, 4:23:02 PM· committed by GitHubparent6a9a7c0
38 files changedLine totals unavailable