Opt-in inactivity expiry for local device claims

Look at the local device ownership and session management code, likely around the daemon and device claim logic. Review issues #1320 and #2162 for context on the design and existing --stale release command. The new environment variable AGENT_DEVICE_SESSION_IDLE_TIMEOUT_MS needs to be integrated to track command activity and trigger session closure, similar to proxy lease expiry. Check how sessions are currently closed and claims released.

Describe the feature

An opt-in idle timeout for local sessions, off by default. For example, AGENT_DEVICE_SESSION_IDLE_TIMEOUT_MS. When a session gets no commands for that long, the daemon closes it the normal way and releases its device claim.

Motivation

Several AI agents share one computer and a few devices. Agents often finish without running close, so their claims stay live until the daemon stops. Other agents then get DEVICE_IN_USE and can't tell an active session from an abandoned one.

We know #1320 made "never reclaim a live owner because it looks inactive" a deliberate rule, and that's a good default. We're asking for this only as an opt-in for machines shared by agents. Proxy leases already expire after 5 minutes without commands, so this would bring the same behavior to local devices.

Related Issues

• #1320: local device ownership design, including the inactivity non-goal
• #2162: added device release --stale, without --force

Written by Claude Opus 5.5

Hope you guys take AI issues 😆

Thanks!