--help, -h and the help subcommand now print to stdout and exit 0, so
the help can be paged and searched. The usage text of a usage error
stays on stderr with exit 2, as does help for an unknown subcommand
("sfdupes help scna"). A failed write of the help exits 1.
Cobra prints help to the command's output writer, which stays stderr,
drops a failed write, and returns no error after help. So run replaces
the help function and the help subcommand: the help goes into a buffer,
then to stdout, and the error sets the exit code.
README "Settings" and goal 4 say so.
Model: opus-5-5
sneak