Remote sessions track whether a viewer is away

What

A remote session is a Claude Code session you watch or control from another place, such as another device or window. These are called viewers or clients. Claude Code now keeps track of whether a viewer is present.

• The layer that streams a session to viewers gains an onViewerSign handler. The away and user signals now mark a viewer as away or present. Before, the only reconnect handling resynced the session after a reconnect.
• Reconnecting ends the away state.
• Closing a remote session now calls endViewerAway("close").
• When a session closes, a new step writes a closing notice ({op:"lease", closing}) to every client connected through a lease, which is the link that holds a client to the session.

Why

Remote sessions can now tell when nobody is watching. Clients still attached when a session shuts down are told it is closing instead of simply losing the connection.