pub const MESSAGE_TURN_KEY: &'static str;Expand description
Message key carrying the host’s turn identity ({"id": "<uuid>"}) in
memory. Never persisted inside a message: 0.10.2 strips only
_synaps_context before a provider request, so an inline key would reach
the wire after a rollback. Saves move the id to a sibling (t on journal
msg records, _turn_ids in the snapshot), which older readers ignore.