feat(receipt-import): refactor product creation and category update to use server actions

frontend/app/kvitto/ReceiptImportClient.tsx

@@ -195,26 +195,15 @@ export default function ReceiptImportClient({ isAdmin }: { isAdmin: boolean }) {
     // eslint-disable-next-line no-console
     console.log('handleCreateProduct: isAdmin =', isAdmin, 'endpoint = /api/products');
     try {
-      // Admin skapar aktiv produkt direkt
-      const createRes = await fetch('/api/products', {
-        method: 'POST',
-        headers: { 'Content-Type': 'application/json' },
-        body: JSON.stringify({ name: row.rawName }),
-      });
-      if (!createRes.ok) {
-        const e = await createRes.json().catch(() => ({}));
-        throw new Error(e.message ?? `HTTP ${createRes.status}`);
-      }
-      const product = await createRes.json() as { id: number; name: string; canonicalName: string | null };
+      const { createProductAction, updateProductCategoryAction } = await import('./actions');
+      
+      // Admin skapar aktiv produkt direkt via Server Action
+      const product = await createProductAction(row.rawName);
 
       // Sätt kategori: AI-förslag har prioritet, annars manuellt val
       const categoryId = row.categorySuggestion?.categoryId ?? (row.selectedCategoryId !== '' ? row.selectedCategoryId : null);
       if (categoryId) {
-        await fetch(`/api/products/${product.id}`, {
-          method: 'PATCH',
-          headers: { 'Content-Type': 'application/json' },
-          body: JSON.stringify({ categoryId }),
-        });
+        await updateProductCategoryAction(product.id, categoryId);
       }
 
       // Uppdatera produktlistan lokalt