Server.loadBuffer(from:named:)

setBuffer(_:named:) carries the text as an argument, which caps it at whatever the platform allows in an argument vector and — over connected(attachingTo:_:) — forbids a newline outright, because a connection sends a command *line*. A path has neither problem: it is short, and tmux opens the file itself. This is the way to put many lines into a buffer from a connected server.

The path is resolved by the tmux server, which for a socket on this machine is this machine.