Auto-reply — retired delivery gate

Confidence thresholds, risk bands, auto_reply_mode, auto_reply_enabled, held_for_review, system acknowledgements, and pre-delivery Expert review no longer decide whether a successful Hermes reply is delivered.

Per ADR-046, every successful Hermes reply is delivered exactly once. Expert review is optional after-the-fact observability and correction. A genuine agent failure returns a failure; Humanwork does not fabricate a system reply or queue substitute.

Legacy database columns or settings may be read for migration/analytics while they are being removed, but no send, serializer, channel, search, or UI path may use them to hide or hold a reply. The historical mode matrix remains available in Git history.