Lifecycle events

Events fire on "<event>" {} handlers and arrive in fn handle(event: Event, lab: Lab). Handler failures are logged, never fatal.

Event	Meaning
vm.starting	A VM has begun booting
vm.ready	The guest agent is responding
vm.stopped	A VM powered off cleanly
vm.crashed	A VM died unexpectedly (includes closing a gui window)
lab.up	The lab finished coming up
lab.down	The lab stopped
snapshot.created	A snapshot was taken
snapshot.restored	A snapshot was restored
template.built	A template build sealed into the store
lab.daemon_crashed	A lab daemon died (no auto-restart)
host.disk_low	Free disk fell below disk_low_percent