Fix part hover preview and localStorage quota on cart creation

src/components/ItemCard.tsx

@@ -1,6 +1,6 @@
-import { useState } from 'react'
+import { useEffect, useState } from 'react'
 import type { Product, Drone, CompleteDrone, KitBuild } from '../types'
-import { useResolvedImage, resolveImageSync } from '../utils/imageCache'
+import { useResolvedImage, resolveImageSync, resolveImage } from '../utils/imageCache'
 
 function fmt(amount: number, currency: string) {
   return new Intl.NumberFormat('en', { style: 'currency', currency }).format(amount)
@@ -26,6 +26,14 @@ export function ItemCard({ item, onEdit, onRemove }: Props) {
   const [hoverImg, setHoverImg] = useState<string | null>(null)
   const [mousePos, setMousePos] = useState({ x: 0, y: 0 })
 
+  // Preload part images into memCache so resolveImageSync works on hover
+  useEffect(() => {
+    if (!isKit) return
+    for (const p of (item as KitBuild).parts) {
+      if (p.image) resolveImage(p.image)
+    }
+  }, [item])
+
   const priceLabel = isKit
     ? kitTotal(item as KitBuild)
     : isDrone