refactor: adjust image height and add top spacing

lib/new-ui/widgets/seed/seed_hero_image.dart

@@ -14,7 +14,7 @@ class SeedHeroImage extends StatelessWidget {
     return CakeImageWidget(
       imageUrl: "assets/new-ui/hero/${name}_$variant.svg",
       width: 200,
-      height: 228.57,
+      height: 175,
     );
   }
 }

lib/new-ui/widgets/seed/seed_page_header.dart

@@ -20,6 +20,7 @@ class SeedPageHeader extends StatelessWidget {
   Widget build(BuildContext context) => Column(
         mainAxisSize: MainAxisSize.min,
         children: [
+          const SizedBox(height: 24),
           ExcludeSemantics(child: image),
           SizedBox(height: imageSpacing),
           Semantics(