@startuml
skinparam backgroundColor #FFFFFF
skinparam defaultFontName Arial
skinparam defaultFontSize 14
skinparam shadowing false
title Candidate and active runtime (conceptual states)
[*] --> Candidate : accepted complete PUT
Candidate --> Refreshing : compilation / execution succeeds
Candidate --> Rejected : compilation / execution error
Refreshing --> Refreshing : yield / continue refresh
Refreshing --> Active : valid document + matching submission
Refreshing --> Superseded : newer write / delete
Active --> Active : Console / input / task completion
Active --> Faulted : callback or refresh fault
Active --> Retired : replace / reset / delete / shutdown
Faulted --> Retired : cleanup or replace
Rejected --> [*]
Superseded --> [*]
Retired --> [*]
@enduml