[create-next-app] Make next.svg viewBox match rendered aspect ratio
The next.svg viewBox was 0 0 394 80 (ratio 4.925:1) but rendered at
width={100} height={20} (ratio 5:1). With Tailwind's height: auto,
the browser computes a different height, triggering the same next/image
warning. Widen the viewBox to 0 0 400 80 (exactly 5:1) to match.