Desktop app: group appears empty in Cowork view; deleting it there silently destroys the full Code group

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?

Environment: Claude Code desktop app v2.1.229, Windows 11 Pro (10.0.26200)

Since session groups became shared across the Code and Cowork sidebars (v2.1.229), a group containing only code sessions renders in the Cowork view as an empty group — with no indication that it has members in the other mode.

Steps to reproduce:

1. In the Code view, create a session group and add several code sessions to it.
2. Switch to the Cowork view. The same group appears there, showing no members.
3. Delete the group from the Cowork view — a user reasonably assumes it is an empty leftover ("what is this empty group?").
4. Return to the Code view: the group and all of its session assignments are gone.

There is no confirmation dialog showing cross-mode membership, and no undo. The sessions themselves survive, but the grouping is destroyed and must be rebuilt from memory. In my case the original membership was unrecoverable: the app's local storage (dframe-group-scopes in the Local Storage leveldb) had already compacted away the pre-delete record by the time I went looking.

Related (distinct triggers, same feature losing user organization): #86843 (creating a new group wipes existing groups), #78812 (groups wiped on account switch).

What Should Happen?

Any of: (a) the Cowork view shows the group's cross-mode membership ("7 code sessions") instead of rendering it empty; (b) deleting a group prompts with its total membership across both modes before proceeding; (c) group deletion is undoable. Ideally all three — a group that looks empty but isn't is a data-loss trap.

Error Messages/Logs

Steps to Reproduce

1. In the Claude Code desktop app (Windows, v2.1.229), open the Code view of the sessions sidebar.
2. Create a custom session group and drag several code sessions into it.
3. Switch to the Cowork view. The same group is listed, but renders with no members and no indication it contains code sessions.
4. Delete the group from the Cowork view (context menu > delete). No confirmation of cross-mode membership is shown.
5. Return to the Code view: the group is gone and all its member sessions have fallen out to ungrouped. There is no undo.

Claude Model

None

Is this a regression?

No, this never worked

Last Working Version

_No response_

Claude Code Version

2.1.229 (Claude Code, bundled with Windows desktop app)

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Other

Additional Information

_No response_