fix(auth): remove duplicate headings and subtitle on register page

src/components/auth/auth-landing.tsx

@@ -81,7 +81,7 @@ export interface AuthLandingCopy {
 	/** Optional success notice rendered above the form (e.g. "registered"). */
 	notice?: ReactNode;
 	promoTitle: ReactNode;
-	promoSubtitle: ReactNode;
+	promoSubtitle?: ReactNode;
 	usersOnlineLabel: string;
 	whoIsOnlineLabel: string;
 	newestCitizensLabel: string;

src/components/auth/auth-promo-card.tsx

@@ -6,7 +6,8 @@ interface AuthPromoCardProps {
 	/** Fully formatted "N users online" label. */
 	onlineLabel: string;
 	title: ReactNode;
-	subtitle: ReactNode;
+	/** Optional supporting line under the title. */
+	subtitle?: ReactNode;
 }
 
 /**
@@ -95,12 +96,14 @@ export function AuthPromoCard({
 				>
 					{title}
 				</h1>
-				<p
-					className="text-xs mt-1.5 mx-auto max-w-[240px] leading-relaxed"
-					style={{ color: "var(--color-text-muted)" }}
-				>
-					{subtitle}
-				</p>
+				{subtitle && (
+					<p
+						className="text-xs mt-1.5 mx-auto max-w-[240px] leading-relaxed"
+						style={{ color: "var(--color-text-muted)" }}
+					>
+						{subtitle}
+					</p>
+				)}
 			</div>
 		</SurfaceCard>
 	);