Every app that imports the kit was shipping a /favicon.ico 404
because none of them wired up Next.js's metadata.icons. This adds
a tiny helper so an app only has to:
export const metadata: Metadata = {
title: brand.product,
icons: brandIcons(brand),
};
brandIcons() returns icon/shortcut/apple entries pointing at
brand.faviconUrl (new optional field, defaults to brand.logoUrl).
MIME type inferred from the URL extension (svg/png/ico).
Brand gains the optional faviconUrl field. Existing apps that just
pass logoUrl keep working — they'll now render the logo as the
favicon by default. Apps that want a separate icon set
faviconUrl explicitly.
First consumer: gscSounds layout — verified /favicon.ico now
serves the proper icon and /icon.svg works too.
