feat: add bulk stock sync from Sheets to Shopify

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

src/app/(dashboard)/creation/page.tsx

@@ -25,6 +25,42 @@ export default function CreationPage() {
   const [stopped, setStopped] = useState(false)
   const abortRef = useRef<AbortController | null>(null)
 
+  // Sync stock
+  const [stockSyncing, setStockSyncing] = useState(false)
+  const [stockResult, setStockResult] = useState<{ updated: number; errors: number } | null>(null)
+  const [stockProgress, setStockProgress] = useState<{ current: number; total: number; title: string } | null>(null)
+
+  const syncStock = async () => {
+    setStockSyncing(true)
+    setStockResult(null)
+    setStockProgress(null)
+    try {
+      const res = await fetch('/api/creation/sync-stock', { method: 'POST', headers: { 'Content-Type': 'application/json' }, body: '{}' })
+      if (!res.body) return
+      const reader = res.body.getReader()
+      const decoder = new TextDecoder()
+      let buffer = ''
+      while (true) {
+        const { done, value } = await reader.read()
+        if (done) break
+        buffer += decoder.decode(value, { stream: true })
+        const lines = buffer.split('\n')
+        buffer = lines.pop() ?? ''
+        for (const line of lines) {
+          if (!line.trim()) continue
+          try {
+            const evt = JSON.parse(line)
+            if (evt.type === 'progress') setStockProgress({ current: evt.current, total: evt.total, title: evt.title })
+            if (evt.type === 'done') setStockResult({ updated: evt.updated, errors: evt.errors })
+          } catch { /* */ }
+        }
+      }
+    } finally {
+      setStockSyncing(false)
+      setStockProgress(null)
+    }
+  }
+
   // Collection
   const [collections, setCollections] = useState<ShopifyCollection[]>([])
   const [detectedCollectionId, setDetectedCollectionId] = useState<string>('')
@@ -174,9 +210,30 @@ export default function CreationPage() {
 
         {/* Étape 0 — Sélection famille */}
         {step === 'famille' && (
-          <div className="bg-slate-800 rounded-xl p-6">
-            <h2 className="text-sm font-semibold text-white mb-4">Choisir une famille</h2>
-            <FamilySelector onSelect={handleSelectTab} />
+          <div className="space-y-4">
+            <div className="bg-slate-800 rounded-xl p-6">
+              <h2 className="text-sm font-semibold text-white mb-4">Choisir une famille</h2>
+              <FamilySelector onSelect={handleSelectTab} />
+            </div>
+            <div className="bg-slate-800 rounded-xl p-6">
+              <h2 className="text-sm font-semibold text-white mb-1">Synchroniser le stock</h2>
+              <p className="text-xs text-gray-400 mb-4">Met à jour le stock Shopify pour tous les produits existants (ceux avec un ID Shopify dans le Sheets).</p>
+              <button onClick={syncStock} disabled={stockSyncing}
+                className="px-4 py-2 bg-amber-700 hover:bg-amber-600 disabled:opacity-50 text-white rounded-lg text-sm font-medium transition-colors">
+                {stockSyncing ? (stockProgress ? `Mise à jour… ${stockProgress.current}/${stockProgress.total}` : 'Chargement…') : 'Synchroniser le stock depuis Sheets'}
+              </button>
+              {stockSyncing && stockProgress && (
+                <p className="mt-2 text-xs text-gray-400 truncate">→ {stockProgress.title}</p>
+              )}
+              {stockResult && (
+                <p className="mt-3 text-sm">
+                  {stockResult.errors === 0
+                    ? <span className="text-green-400">✓ {stockResult.updated} produit{stockResult.updated > 1 ? 's' : ''} mis à jour</span>
+                    : <span className="text-amber-400">✓ {stockResult.updated} mis à jour — ⚠ {stockResult.errors} erreur{stockResult.errors > 1 ? 's' : ''}</span>
+                  }
+                </p>
+              )}
+            </div>
           </div>
         )}