[BUG] Per-device session visibility — sidebar leaks session titles across machines on one account

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?

The desktop app sidebar shows session titles from ALL machines signed into
the same account. I use Claude Code desktop on two Windows laptops — a
personal one and a client-owned one for consulting work. On the personal
laptop, the sidebar's "Other" section lists sessions that were created on
the client laptop (and confirmed vice versa).

I verified those sessions do not exist in the personal machine's local
session store — only titles/metadata sync account-wide, but that is enough
to leak confidential information in both directions: client names and
engagement topics appear on my personal machine, and personal session
titles appear on a client-owned (potentially monitored) machine.

There is no setting to control this, and neither the "Other" section nor
cross-device session visibility is documented.

What Should Happen?

Either:

1. A setting to scope the sidebar session list to the local machine only

(per-device or per-project visibility), or

1. Workspace/profile separation within one account, so sessions from one

machine/profile never appear on another.

At minimum, document the current behavior — users handling
client-confidential work need to know that session titles sync across all
devices on the account.

Error Messages/Logs

None — no errors. This is behavior, not a crash. Verified via the session
management tools that the cross-device entries shown in the sidebar have no
corresponding local session records on the machine displaying them.

Steps to Reproduce

1. Sign into the Claude Code desktop app with the same account on two

different machines (A and B).

1. On machine B, run a few sessions in a project folder that does not

exist on machine A.

1. On machine A, open the desktop app sidebar with a project selected.
2. The "Other" section lists the machine-B session titles, even though

those sessions are not in machine A's local session store.

Claude Model

Not sure / Multiple models

Is this a regression?

No, this never worked

Last Working Version

N/A

Claude Code Version

2.1.237

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

Use case: independent consultant with a deliberately isolated setup —
client work confined to a client-owned laptop, personal work on a personal
laptop, no file sync between them. The account-level title sync is the
only remaining bridge, and it undermines that isolation at the metadata
level.

Archiving the foreign sessions from the sidebar is only cosmetic — new
sessions from the other machine keep appearing. The only current
workaround appears to be a second paid account per machine.

Happy to provide more detail. Please consider this partly a privacy issue,
not just a UX request.