Remote sessions and hosts can record that they left, and why

What

With Remote Control, one Claude Code session can reach another session or a remote host (a peer). Claude Code can now record that a peer or session left on purpose, and why.

• Closing a remote session through dispose can now take a leftFor value. When it is set, the session records at: "left" and passes leftFor on to the close step.
• The registry of remote-tools hosts now tracks each host's capabilities and which instance announced it. It also records why a host was withdrawn, through withdrawnFor.
• The session report has a new left state. It shows as state: "off" with a reason taken from leftFor. Before, the reason could only be serving_off or not_announced.
• When a peer that signed off has leftFor set, the message saying it "could not be reached from this session" is now built from that value. Before, it always asked the user to open Claude on that machine again with Remote Control on.

The same finding also notes two other changes. Cloud-session status and stopping events now show no notice text. Permission asks in a cloud session now pass forMcpSkill when the tool's metadata has mcpSkill.

Why

A peer or host that left on purpose is no longer reported as simply off or unannounced. Claude, and anyone reading the session report, gets the actual reason, so a deliberate departure no longer leads to the generic advice to turn Remote Control back on.