DL-398
Reload hands control state to the relaunched agent through controlProducer.Restart, called after stream.Stop() and before StartAgent: it advances the epoch and subscription generation, which ends the old stream and fences its acks; stamps replay_complete as seq 1; renumbers every unacked retained op behind it; and resets the ack cursor. The lift is the first op, and unacked ops are redelivered at least once. No hold-for-replay on reload
Status: Active (Matt, 2026-10-03)