fix: retry 429 avec backoff + sérialisation uploadAll + 409 traité comme skipped

src/hooks/useImages.ts

@@ -249,8 +249,13 @@ export function useImages() {
     [items, update],
   )
 
-  const uploadAll = useCallback(() => {
-    items.filter((i) => i.status === 'ready').forEach((i) => uploadOne(i.id))
+  const uploadAll = useCallback(async () => {
+    const ready = items.filter((i) => i.status === 'ready')
+    for (const item of ready) {
+      await uploadOne(item.id)
+      // Pause de 500ms entre chaque upload pour éviter le rate limit Shopify
+      await new Promise(r => setTimeout(r, 500))
+    }
   }, [items, uploadOne])
 
   const removeItem = useCallback((id: string) => {

src/lib/shopify.ts

@@ -118,12 +118,30 @@ export async function uploadProductImage(
   const existingUrl = await productImageExists(shopifyProductId, filename)
   if (existingUrl) return { url: existingUrl, skipped: true }
 
+  // Retry avec backoff exponentiel (gère le 429 rate limit)
+  const MAX_RETRIES = 4
+  let delay = 1000
+
+  for (let attempt = 0; attempt <= MAX_RETRIES; attempt++) {
     const res = await fetch(`${baseUrl}/products/${shopifyProductId}/images.json`, {
       method: 'POST',
       headers,
       body: JSON.stringify({ image: { attachment: imageBase64, filename } }),
     })
 
+    // 409 Conflict = image déjà présente → traiter comme skipped
+    if (res.status === 409) {
+      return { url: `https://placeholder/already-exists/${filename}`, skipped: true }
+    }
+
+    // 429 Too Many Requests → attendre et réessayer
+    if (res.status === 429 && attempt < MAX_RETRIES) {
+      const retryAfter = parseInt(res.headers.get('Retry-After') ?? '0', 10)
+      await new Promise(r => setTimeout(r, retryAfter > 0 ? retryAfter * 1000 : delay))
+      delay *= 2
+      continue
+    }
+
     if (!res.ok) {
       const body = await res.text()
       throw new Error(`Shopify upload error: ${res.status} — ${body}`)
@@ -135,3 +153,6 @@ export async function uploadProductImage(
     }
     return { url: data.image.src as string }
   }
+
+  throw new Error('Shopify upload error: trop de tentatives (rate limit persistant)')
+}