Function send 

pub fn send(target: &str, from: &str, body: &str, owlery: &Path) -> SendOutcome

High-level fire-and-forget send. Validates the perch exists and the body is non-empty, delivers, and maps the delivery path to a SendOutcome. No I/O, no exit — the caller renders the outcome.

Reply routing is this same call with from set to the replier’s id: the structural from the original message carried names the target, and the reply’s own from lets the original sender reply back in turn.