Return no record when expiresAt is at or before the current time.
Atomically create a registration. An identical retry is idempotent; a
conflicting live registration for the same key MUST reject. A successful
return MUST provide immediate read-your-writes consistency through get()
so the SDK can verify trusted authorization provenance before dispatch.
Remove provenance after a definitively synchronous terminal response.
Atomically mark a live registration as requiring durable mutation
settlement. The update MUST be immediately visible through get().
Process-local registration store. Multi-process or restart-safe receivers must inject a shared durable implementation.