Bug: Chat UI sessions don't sync between paired devices (terminal tabs do)

Summary

I have two Orca installs paired in both directions over Tailscale. Sessions started in the Chat UI never show up on the other device, not even after restarting the client there. Generic terminal and Claude Code terminal tabs created the same way show up on the other device immediately. So the network and pairing work, and the problem is specific to how Chat UI sessions are synced or listed.

Update: A phone on the same tailnet does see the MacBook's Chat UI sessions. The tab and its messages appeared on the phone right away, and a message sent from the phone appeared on the MacBook right away. The Mac Mini still doesn't show that chat. So Chat UI sync works in general, and the bug seems specific to syncing between the two paired desktops.

Environment

	MacBook (primary)	Mac Mini
Orca version	1.4.218	1.4.218
macOS	27.0.1 (26A434)	27.0.1
Hardware	Mac17,2	Mac Mini
Tailscale	1.102.4	1.102.4
Claude Code	2.1.286	2.1.286

The devices are paired in both directions over a Tailscale tailnet.
A phone (iPhone 16 Pro / iOS 27.0.1 / Orca v 0.0.51) is also connected over the same tailnet.
Agent: Claude Code (Claude Opus 5.5).

Steps to reproduce

Install Orca on two Macs and pair them in both directions over Tailscale.
On Device A, open a new tab using the Chat UI and send a message.
Check the session list on Device B.
Send more messages on Device A and check Device B again.
Restart the Orca client on Device B and check again.

Expected

The Chat UI session appears on Device B, as terminal tabs do.

Actual

The Chat UI session never appears on Device B, not after more messages and not after a restart.

Test matrix

Session type	Created on	Created in environment	Shows up on other device?
Chat UI	MacBook	MacBook (local)	❌ No, not even after restarting the Mac Mini client
Chat UI	Mac Mini	Mac Mini (local)	❌ No
Chat UI	Mac Mini	MacBook (remote environment)	❌ No, the MacBook doesn't show it even though it runs there
Generic terminal (×2)	MacBook	MacBook (local)	✅ Yes, immediately
Claude Code terminal tab	MacBook	MacBook (local)	✅ Yes, immediately
Chat UI	MacBook	MacBook (local)	✅ Phone: yes, immediately, and phone-sent messages show on the MacBook right away. ❌ Mac Mini: no

Observations

Not a network or pairing issue. Terminal tabs sync instantly in both directions over the same link.
Not a live-update issue. A restart doesn't make the chat appear, so the chat isn't just missing from a live view. It never reaches the other device.
It happens in both directions. Neither device's Chat UI sessions sync.
Sessions seem to belong to the app that opened them, not the machine they run on. A Chat UI session the Mac Mini opened in the MacBook's environment still doesn't show on the MacBook. Terminal tabs seem to be tracked on the machine itself.
Chat UI sync works with the phone but not between the desktops. The MacBook's Chat UI sessions sync to the phone in both directions, both the tab and its messages, right away. So Chat UI sessions are shared. They just never reach the other paired desktop. The cause is likely in desktop-to-desktop pairing, for example the Mac Mini subscribes to terminal sessions but not chat sessions, or it uses a different session-listing path than the mobile client.

Workaround

Start Claude Code as a terminal tab, not a Chat UI session, when it needs to be visible on both devices.

Test log (condensed)

Started a Chat UI session on the MacBook, then checked the Mac Mini: not visible.
Sent a second message to see if more activity would trigger sync: still not visible.
Restarted the Orca client on the Mac Mini: still not visible.
Created two Generic terminal windows and one Claude Code terminal tab on the MacBook: all appeared on the Mac Mini immediately.
Created Chat UI tabs on the Mac Mini, one in the Mac Mini's environment and one in the MacBook's remote environment: neither appeared on the MacBook.
Started a new Chat UI session on the MacBook and opened Orca on a phone connected over Tailscale. The tab and its messages appeared on the phone immediately. A message sent from the phone appeared on the MacBook immediately. The same chat was still not visible on the Mac Mini.