Properties
name
key
chatId:senderId per group participant).
reason
'unforwardable': it kept no checkpoint; 'changed': a forwarded flow changed on this replica.
startedAt?
startState?
c.state, when that was plain JSON.
trace?
BotConfig.telemetry): W3C trace context of its last turn on the previous
replica, to link a migrated conversation’s spans to it ('restart' does it itself).