Turn one request into recipient notices
What It Does
A request worker receives publication work.
The Flow
When Something Fails
The hop rows identify each retry boundary, any state left behind and the available observer. Derived request and occurrence identities prevent repeated acceptance and duplicate recipient notices. Up to four items process concurrently; sorted transaction-scoped folding locks serialize matching identities, with hash collisions causing only extra waiting.
Open Design Questions
System audiences follow the reserved-workspace alert path. Cancellation items follow withdrawal processing. Future-dated work waits until its earliest processing time.