fix(products): keep newly uploaded image when SSE list is stale

The live product stream was replacing the catalog with an older payload, so the new photo flashed then jumped back. Keep the newer file_id and stop resetting the img on unrelated price ticks.

Co-authored-by: Cursor <cursoragent@cursor.com>

src/components/ProductImage.vue

@@ -29,16 +29,26 @@ const props = withDefaults(
   }
 )
 
+function productImageKey(product?: ProductImageSource): string {
+  return [
+    product?.file_id ?? '',
+    product?.file?.id ?? '',
+    product?.file?.full_src ?? '',
+    product?.file?.src ?? '',
+    product?.file?.url ?? '',
+    product?.img ?? '',
+  ].join('|')
+}
+
 const currentSrc = ref(resolveProductImageSrc(props.product))
 const usingFallback = ref(false)
 
 watch(
-  () => props.product,
-  (product) => {
+  () => productImageKey(props.product),
+  () => {
     usingFallback.value = false
-    currentSrc.value = resolveProductImageSrc(product)
+    currentSrc.value = resolveProductImageSrc(props.product)
   },
-  { deep: true }
 )
 
 function handleError() {