Desktop app: creating a new session group wipes all existing sidebar groups (dframe-group-scopes overwritten instead of merged)

Environment

• Claude desktop app 1.30096.1 (MSIX / Microsoft Store), bundled Claude Code 2.1.229
• Windows 11 Pro 10.0.26200, locale ko-KR

What happened

The user had several custom session groups in the Code-tab sidebar (roughly one per project: infotravelog, ondaeri, Taekwang, Ai회사만들기, …), created over the past weeks.

Today the user created a new group ("ondaeri-study") and dragged one existing session into it. At that exact moment, all previously existing groups disappeared: every previously grouped session fell into "No group" (그룹 없음), and only the newly created group remained in the sidebar.

What we found on disk

Sidebar groups are persisted in %APPDATA%\Claude\claude_desktop_config.json under preferences.epitaxyPrefs["dframe-group-scopes"].

After the incident, that key contains only the newly created group:

"dframe-group-scopes": {
  "<orgId>/<userId>": {
    "groups": [ { "id": "cg-…", "name": "ondaeri-study" } ],
    "assignments": { "code:local_…": "cg-…", "code:local_…": "cg-…" },
    "order": { "cg-…": [ "code:local_…", "code:local_…" ] }
  }
}

i.e. the write replaced the whole scope object instead of merging with the existing groups/assignments. The Local Storage (leveldb) copy mirrors the same already-clobbered state, and no backup of the previous value exists anywhere on disk, so the user's grouping data was unrecoverable.

Expected behavior

Creating a group or assigning a session to a group should merge into the existing dframe-group-scopes entry, not replace it wholesale.

Notes

• Session data itself was unaffected (%APPDATA%\Claude\claude-code-sessions\**\local_*.json all intact); only the grouping metadata was lost.
• We recovered by regenerating groups from each session's originCwd, but the original user-defined grouping was permanently lost.
• Filed on behalf of the affected user from a Claude Code session.