fix(scanner): resolve stale closure in handleCardScanned

- Add scannedCardsRef to track latest queue state
- Use functional updater in setScannedCards to avoid stale mergeScannedCardEntry input
- Return cardEntry.id synchronously from handleCardScanned so onScanImageUploaded fires

This fixes the scanner queue stopping after 1 card (required page refresh to see more).

lib/use-scanner-queue.js

@@ -45,6 +45,11 @@ export function useScannerQueue({ user, sessionDestination, scanDefaults, deckMo
   const addingInFlightRef = useRef(new Set());
   const [addingCardIds, setAddingCardIds] = useState(() => new Set());
   const cartPersistTimerRef = useRef(null);
+  const scannedCardsRef = useRef(scannedCards);
+
+  useEffect(() => {
+    scannedCardsRef.current = scannedCards;
+  }, [scannedCards]);
 
   const persistCart = (cards, selection) => {
     saveScannerCart({
@@ -162,22 +167,25 @@ export function useScannerQueue({ user, sessionDestination, scanDefaults, deckMo
     setUndoStack((prev) => prev.filter((u) => u.cardId !== cardId));
   }, []);
 
-  const handleCardScanned = (cardData) => {
+  const handleCardScanned = useCallback((cardData) => {
     setAutoRouteError(null);
 
     const { cardEntry, scannedCards: nextQueue } = mergeScannedCardEntry(
-      scannedCards,
+      scannedCardsRef.current,
       cardData,
       scanDefaults
     );
-    setScannedCards(nextQueue);
-    setSelectedCards((prev) => {
-      const next = new Set([...prev, cardEntry.id]);
-      persistCart(nextQueue, next);
-      return next;
+    setScannedCards((prev) => {
+      const { cardEntry: ce, scannedCards: nq } = mergeScannedCardEntry(prev, cardData, scanDefaults);
+      setSelectedCards((ps) => {
+        const n = new Set([...ps, ce.id]);
+        persistCart(nq, n);
+        return n;
+      });
+      return nq;
     });
     return cardEntry.id;
-  };
+  }, [scanDefaults]);
 
   const incrementCardQuantity = (cardId) => {
     setScannedCards((prev) =>