feat: add external link confirmation dialog for product URLs

Show an external link icon on ItemCard and CandidateCard that opens a
confirmation dialog before navigating to product URLs.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/client/components/ItemCard.tsx

@@ -10,6 +10,7 @@ interface ItemCardProps {
 	categoryName: string;
 	categoryIcon: string;
 	imageFilename: string | null;
+	productUrl?: string | null;
 	onRemove?: () => void;
 }
 
@@ -21,9 +22,11 @@ export function ItemCard({
 	categoryName,
 	categoryIcon,
 	imageFilename,
+	productUrl,
 	onRemove,
 }: ItemCardProps) {
 	const openEditPanel = useUIStore((s) => s.openEditPanel);
+	const openExternalLink = useUIStore((s) => s.openExternalLink);
 
 	return (
 		<button
@@ -31,6 +34,38 @@ export function ItemCard({
 			onClick={() => openEditPanel(id)}
 			className="relative w-full text-left bg-white rounded-xl border border-gray-100 hover:border-gray-200 hover:shadow-sm transition-all overflow-hidden group"
 		>
+			{productUrl && (
+				<span
+					role="button"
+					tabIndex={0}
+					onClick={(e) => {
+						e.stopPropagation();
+						openExternalLink(productUrl);
+					}}
+					onKeyDown={(e) => {
+						if (e.key === "Enter" || e.key === " ") {
+							e.stopPropagation();
+							openExternalLink(productUrl);
+						}
+					}}
+					className={`absolute top-2 ${onRemove ? "right-10" : "right-2"} z-10 w-6 h-6 flex items-center justify-center rounded-full bg-gray-100/80 text-gray-400 hover:bg-blue-100 hover:text-blue-500 opacity-0 group-hover:opacity-100 transition-all cursor-pointer`}
+					title="Open product link"
+				>
+					<svg
+						className="w-3.5 h-3.5"
+						fill="none"
+						stroke="currentColor"
+						viewBox="0 0 24 24"
+					>
+						<path
+							strokeLinecap="round"
+							strokeLinejoin="round"
+							strokeWidth={2}
+							d="M18 13v6a2 2 0 01-2 2H5a2 2 0 01-2-2V8a2 2 0 012-2h6M15 3h6v6M10 14L21 3"
+						/>
+					</svg>
+				</span>
+			)}
 			{onRemove && (
 				<span
 					role="button"