Command shape
Options struct + NewCmdXxx constructor + pure runFunc three-part separation.
Decisions
byob-command-shape.1— Three-part command shape with a runF test-injection hookbyob-command-shape.3— Cobra command groups for semantic help; root only aggregatesbyob-command-shape.4— Ship shell completions via cobra's completion subcommandbyob-command-shape.5— PersistentPreRunE on root for app-wide middlewarebyob-command-shape.6— Cobra flag-group helpers over hand-rolled validationbyob-command-shape.7— Implement pflag.Value for custom flag types