Re-mints the README hero: the template shipped a generic card whose wordmark
literally read "logo" with a truncated subtitle. generateHero() now composes
the brand's own white mark + real name + full tagline + github/domain footer,
driven by a package.json "brand" block — one template, every org. Also renames
dist SVG sources brand-neutral (logo.svg, favicon.svg, …) so the shared build is
correct for every brand (they were hanzo-prefixed after the earlier port).