Fix TDZ crash: move expandedCard declaration before useEffect that references it

src/pages/HomePage.jsx

@@ -65,6 +65,8 @@ function HomePage() {
     totalCopies: cards.reduce((s, c) => s + getTotal(c), 0),
   }), [cards, getTotal]);
 
+  const expandedCard = cards.find(c => c.id === expandedCardId);
+
   const filteredCards = useMemo(() => {
     let result = cards;
     if (debouncedSearch) {
@@ -83,8 +85,6 @@ function HomePage() {
     return sorted;
   }, [cards, debouncedSearch, typeFilter, ownedOnly, sortBy, getTotal]);
 
-  const expandedCard = cards.find(c => c.id === expandedCardId);
-
   if (loading) return <p style={{ padding: '1rem', color: '#666' }}>Loading cards…</p>;
   if (error)   return <p style={{ padding: '1rem', color: '#c04040' }}>Error: {error}</p>;