route

Route payload to exactly recipient, crossing the core if recipient is behind another server.

• Directory names this server ⇒ deliver straight down the player's local link.

• Directory names another server ⇒ a single-addressee Seam.sendTo across the core to that one server, which delivers it locally.

• Directory returns null ⇒ the frame is dropped here (the recipient is unattached/unknown; the caller resends on convergence). It is never fanned to more than one destination.