agent_ui: Activate workspace from terminal notifications (#57096)

We weren't activating and focusing the right thing before.

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 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
938490639aBen Brandt committed on 5/19/2026, 9:55:02 AM· committed by GitHubparent8708a6f
1 file changedLine totals unavailable