tmux session_check_name() silently rewrites '.' to '_', so a dotted
party name desyncs from its tmux session and every -t lookup fails
(verified on tmux 3.3a through 3.6b). Leading-dash names can never be
addressed through the CLI parsers.
tmux-party: share a tmux session with people on the same UNIX host.
Single-file POSIX shell (party) with a filesystem + tmux server-access
trust model. See README.md.
