pub(crate) fn send_message_outcome(to: &str, result: &Value) -> Result<String>Expand description
What SendMessage tells the sender, from srv’s /agentmux/reactive/inject
body. Each answer keeps its first word (Delivered, QUEUED, HELD) so
existing prompts keep working, and adds the message id and the receiver’s
condition where srv’s answer already implies it
(SPEC_JEKT_DELIVERY_STATES_AND_MAILBOX_2026_10_01.md §5.2, Phase 0 item 3).