Podcasts take the home page banner

The arcade has had the banner under the clock since it opened. It goes to the podcasts now: same box, same colours, flat on the page, with the studio picture from /podcasts where the game covers were.

Built in src/app/podcast-banner.tsx; the arcade's banner is removed, not kept beside it.

Not to deploy on its own. /podcasts still says there is nothing to hear, so a banner saying Now Open would point at a page that contradicts it. It ships with SC-55 or with an interim line on the page, whichever is first.

Unblocked

/podcasts has both episodes on it now, so the banner and the page agree. They ship together.