fix: include quantity in getAllItems select, createItem values, and updateItem type

Quantity was missing from three places in item.service.ts:
- getAllItems didn't select it (API returned undefined)
- createItem didn't pass it to insert (always used DB default of 1)
- updateItem type didn't include it (silently stripped from updates)

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

src/server/services/item.service.ts

@@ -12,6 +12,7 @@ export function getAllItems(db: Db = prodDb) {
 			name: items.name,
 			weightGrams: items.weightGrams,
 			priceCents: items.priceCents,
+			quantity: items.quantity,
 			categoryId: items.categoryId,
 			notes: items.notes,
 			productUrl: items.productUrl,
@@ -63,6 +64,7 @@ export function createItem(
 			name: data.name,
 			weightGrams: data.weightGrams ?? null,
 			priceCents: data.priceCents ?? null,
+			quantity: data.quantity ?? 1,
 			categoryId: data.categoryId,
 			notes: data.notes ?? null,
 			productUrl: data.productUrl ?? null,
@@ -80,6 +82,7 @@ export function updateItem(
 		name: string;
 		weightGrams: number;
 		priceCents: number;
+		quantity: number;
 		categoryId: number;
 		notes: string;
 		productUrl: string;