feat: add quantity support to totals, UI, and thread resolution

- totals.service: multiply weight/cost sums by quantity in category and global totals
- setup.service: multiply by quantity in getAllSetups SQL subqueries; expose quantity in getSetupWithItems item list
- thread.service: explicitly pass quantity: 1 when inserting resolved item
- ItemForm: add Quantity number input (min=1, default=1) after price field
- ItemCard: show ×N badge next to item name when quantity > 1
- CollectionView: pass quantity prop to ItemCard in both filtered and grouped views
- $setupId.tsx: pass quantity to ItemCard; multiply by quantity in client-side per-setup totals
- WeightSummaryCard: multiply by quantity in all chart and legend weight calculations
- useItems / useSetups: add quantity to ItemWithCategory / SetupItemWithCategory interfaces

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/client/components/ItemCard.tsx

@@ -8,6 +8,7 @@ interface ItemCardProps {
 	name: string;
 	weightGrams: number | null;
 	priceCents: number | null;
+	quantity?: number;
 	categoryName: string;
 	categoryIcon: string;
 	imageFilename: string | null;
@@ -22,6 +23,7 @@ export function ItemCard({
 	name,
 	weightGrams,
 	priceCents,
+	quantity,
 	categoryName,
 	categoryIcon,
 	imageFilename,
@@ -122,9 +124,16 @@ export function ItemCard({
 				)}
 			</div>
 			<div className="p-4">
-				<h3 className="text-sm font-semibold text-gray-900 mb-2 truncate">
-					{name}
-				</h3>
+				<div className="flex items-center gap-1.5 mb-2">
+					<h3 className="text-sm font-semibold text-gray-900 truncate min-w-0">
+						{name}
+					</h3>
+					{quantity != null && quantity > 1 && (
+						<span className="shrink-0 inline-flex items-center px-1.5 py-0.5 rounded-full text-xs font-medium bg-gray-100 text-gray-600">
+							&times;{quantity}
+						</span>
+					)}
+				</div>
 				<div className="flex flex-wrap gap-1.5">
 					{weightGrams != null && (
 						<span className="inline-flex items-center px-2 py-0.5 rounded-full text-xs font-medium bg-blue-50 text-blue-400">