B2B-88: add starter kit structure and elements

app/(marketing)/_components/site-header.tsx

@@ -0,0 +1,16 @@
+import { Header } from '@kit/ui/marketing';
+
+import { AppLogo } from '~/components/app-logo';
+
+import { SiteHeaderAccountSection } from './site-header-account-section';
+import { SiteNavigation } from './site-navigation';
+
+export function SiteHeader() {
+  return (
+    <Header
+      logo={<AppLogo />}
+      navigation={<SiteNavigation />}
+      actions={<SiteHeaderAccountSection />}
+    />
+  );
+}