Self-hosted runner: idle limit from Anthropic and server turn signals

What

The self-hosted runner is the program you run on your own machines to host Claude Code sessions. It can already release a session after the user has been idle for a while. That idle handling has grown.

• Idle limit from Anthropic. When --release-idle-session-min is not set, the runner can take an idle limit from Anthropic's control plane, Anthropic's managing server. Your own --release-idle-session-min setting overrides it. A default can also come from CCR_SHR_IDLE_RELEASE_DEFAULT_MINUTES.
• Safety checks. A session is released only if its code checkouts are clean and its folder holds only what the runner put there; sessions with unsaved work are kept. The folder check uses /proc. The check is skipped for sessions that may continue without the user, such as scheduled prompts or teammate agents.
• Turn signal. Session assignments from the server now carry a turn_signal saying whose turn it is. The runner logs it, tracks it in sessionTurnState, passes it to sessions through onNoTurnSignal, and clears it on exit. New names self_hosted_server_idle_limit and self_hosted_turn_signal were added, along with three constants for a reply-gate policy.
• Lost-files mark. A per-session .disk-mark file lets a session be told if its files were lost.
• Help and warnings. Help text now documents --release-idle-session-min (env SELF_HOSTED_RUNNER_SESSION_IDLE_MS), --hold-idle-file (env SELF_HOSTED_RUNNER_HOLD_IDLE_FILE) and --max-hold-min. The runner warns when --release-idle-session-min is only spaces (read as 0, so idle sessions are kept) or is last with no value (ignored). The settings line notes when the limit was sent by Anthropic's control plane.

Why

If you operate a self-hosted runner, sessions may now be kept alive or released on a schedule Anthropic sets, not only your own. Set --release-idle-session-min if you want to control the limit yourself.