[BUG] Session history has no migration path between machines, and CLI/Desktop app maintain disconnected session stores

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?

When migrating to a new PC, there is no supported way to transfer Claude Code session history. I manually copied the entire ~/.claude directory (including ~/.claude/projects/<project>/*.jsonl) to the new machine.

CLI works: claude --resume in the project directory correctly lists and reopens the old sessions.
Desktop app does not: the same sessions do not appear in the Desktop app's Recents list for that project, even after explicitly opening the identical project folder via "Open Folder...". There appears to be no way to make the Desktop app pick up existing session files.
This suggests the CLI and Desktop app maintain separate session indexes, rather than reading from a shared source of truth.

This was surprisingly hard to diagnose since there's no documentation explaining the CLI/Desktop split, or why an existing, valid session folder isn't picked up by the Desktop app.

What Should Happen?

1. A documented, supported way to migrate session history between machines (even a simple file-copy procedure, if that's the intended mechanism).
2. Ideally, an explicit export/import feature in the Desktop app for session history.
3. Longer-term, the CLI and Desktop app should read from the same session index so switching between them — or moving machines — doesn't fragment history.

Error Messages/Logs

Steps to Reproduce

1. Brand new PC with clean install of Claude Code and Desktop App
2. Copied the entire ~/.claude directory (including ~/.claude/projects/<project>/*.jsonl) to the new machine
3. CLI works: claude --resume in the project directory correctly lists and reopens the old sessions.
4. Desktop app does not: the same sessions do not appear in the Desktop app's Recents list for that project, even after explicitly opening the identical project folder via "Open Folder...".

Even Claude can't solve it.

Claude Model

None

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.220

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

_No response_