Add the split-screen auth shell and its card components

web/frontend/app/features/auth/components/AuthCardHeading.tsx

@@ -0,0 +1,13 @@
+interface AuthCardHeadingProps {
+    title: string;
+    subtitle: string;
+}
+
+const AuthCardHeading = ({ title, subtitle }: AuthCardHeadingProps) => (
+    <div className="flex flex-col gap-1.5">
+        <h1 className="text-[1.875rem]">{title}</h1>
+        <p className="text-[var(--color-muted)]">{subtitle}</p>
+    </div>
+);
+
+export default AuthCardHeading;