Active instances are automatically paused after this much inactivity.
A student can reactivate their instance on their own using the
“Wake” link in the instance table, without teacher intervention.
Format: Go duration like 1h, 30m, 2h30m.
Use 0 to disable auto-pause.
Changes are persisted in state.json on the server and
survive restarts. The environment variable
POCKETHOSTER_IDLE_TIMEOUT (if set and non-empty) takes
precedence at boot.