agent_ui: Route MCP configuration to active workspace (#61882)

# Objective

- Prevent MCP extension configuration dialogs from appearing when
switching to background workspaces.
- Closes FR-145.

## Solution

- Route configuration requests through the active application window and
workspace, while keeping uninstall settings cleanup global.

## Testing

- Added a regression test covering active and retained background
workspaces.

## 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)
- [x] Tests cover the new/changed behavior
- [x] Performance impact has been considered and is acceptable

---

Release Notes:

- Agent: Fixed MCP extension configuration dialogs appearing in other
workspaces.
f9a5bf9181Ben Kunkle committed on 7/30/2026, 3:10:06 PM· committed by GitHubparentcdf3ccd
1 file changedLine totals unavailable