pub fn parse_slash_line(s: &str) -> Option<(&str, &str)>Expand description
Parse "/cmd args..." into (cmd, args) when the leading / is a
command invocation. Returns None when the / is actually part of a
filesystem path, URL, or any other text the user wants sent to the
agent verbatim.
A valid command name is ASCII alphanumeric + _/-, followed by
whitespace or end-of-input. /Users/me, /tmp, /https://...,
/path/with/mixed/字符 all fail the shape test and fall through to
agent dispatch.