Per-subcommand arguments for fix. Currently a placeholder — the --yes
flag lives at the top level (global), so nd300 fix --yes,
nd300 --yes fix, nd300 -f -y, and nd300 -y -f all work and share the
same field on Nd300Cli. New fix-specific options can be added here later
without affecting the legacy -f flag form.
Action subcommands. These are equivalent to the long-running action flags
(-d, -f, --update, --clear-dns, --uninstall) — both forms are
supported and mean the same thing. The subcommand form is the preferred way
going forward; the flag form is kept so existing scripts continue to work.