[BUG] Desktop app: side ("btw") sessions no longer shown under their parent session in sidebar

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

In the Claude desktop app (Code tab, Windows 11), side sessions forked from a main session ("btw" sessions) used to appear nested under their parent session in the left sidebar. Now only the parent sessions are listed. The side sessions still exist (not archived), but they don't show under their parent, and there is no expand arrow or count on the parent row.

Tried switching sidebar grouping between "project" and "date"; no change.

Impact:
When btw sessions were shown in the sidebar, I could see at a glance which ones were still running (the blue in-progress dot) and jump straight to the one I needed. Now:

• I can't tell whether a btw session is still running or has finished its task.
• After switching to another session, there is no quick way to get back to the btw session that was just working.

This makes working with several btw sessions in parallel much harder to follow.

App version: Claude desktop 2.37337.1.0 (Windows 11 Pro for Workstations)

What Should Happen?

btw sessions appear under their parent session in the sidebar, with their running/finished status indicator, as before.

Error Messages/Logs

Steps to Reproduce

1. Open the Claude desktop app (Code tab) on Windows 11.
2. In a main session, start a side ("btw") session.
3. Look at the left sidebar.
4. The btw session is not shown under its parent session. The parent row has no expand arrow or count, and the btw session's running/finished indicator can't be seen anywhere in the sidebar.
5. Switching sidebar grouping between "project" and "date" doesn't change this.

Claude Model

Opus

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.295 (Claude Code, bundled in Claude desktop 2.37337.1)

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Other

Additional Information

This is a UI issue in the Claude desktop app's Code tab sidebar, not in the terminal CLI.

<img width="1715" height="817" alt="Image" src="https://github.com/user-attachments/assets/14f1467b-f5a8-427a-8907-3fa1bae079a3" />