Add FormatError helper and consolidate error rendering

[digitalghost-dev]

• Create cmd/utils/errors.go and add FormatError(message string) string function to centralize the repeated styling.ErrorBorder.Render(styling.ErrorColor.Render("✖ Error!"), ...) pattern

This will replace 10 call sites across validateargs.go, connection.go, cli.go, pokemonflagset.go, and model_input.go