pub const ROOT: &str = "/";Expand description
The route a connection has not stated: the application’s own root.
One constant rather than an empty string, because “the client did not say” and “the client is
at the root” are the same page and a program matching on session.path should not have to
spell both. Every caller that has no route — beck test, the differential harness, a
benchmark, a read model — passes through here rather than writing "/" again.