[Bug] Gmail plugin install is accepted but Google authorization prompt never appears

## Summary

A Gmail plugin installation request can be accepted, but Buzz Desktop never surfaces the Google authorization/consent prompt. The connection remains incomplete and no Gmail tools become available to the managed agent.

The same missing authorization handoff has also been observed when attempting to connect Google Calendar.

## Environment

- macOS
- Buzz Desktop 0.5.11 when first reproduced
- The problem persisted after installing the Buzz update offered on August 16, 2026 and restarting the app
- Exact post-update version was not captured
- Managed agent session using `buzz-acp`

## Steps to reproduce

1. From a managed agent session, request installation/connection of the Gmail plugin.
2. Approve the installation request.
3. Observe Buzz Desktop for the expected Google authorization/consent flow.
4. Restart Buzz Desktop after installing the available update.
5. Retry the Gmail installation/connection request.

## Expected behavior

Buzz Desktop displays a Google authorization prompt or otherwise directs the user into a working OAuth consent flow. After authorization, Gmail tools become available to the managed agent.

## Actual behavior

- The installation request is accepted but remains incomplete.
- No Gmail/Google authorization prompt appears.
- No Plugins or Connections section is visible in Settings to resume the flow manually.
- No Gmail mailbox tools become available to the managed agent.
- Restarting after installing the available Buzz update and retrying does not change the behavior.

## Additional notes

- A search of open issues did not find a clearly matching report.
- No account identifiers, email addresses, channel IDs, message IDs, or other personal information are included here.