feat(admin): refactor product management components for improved state handling and data fetching

frontend/app/admin/products/actions.ts

@@ -97,6 +97,8 @@ export async function updateProductWithTags(formData: FormData, tags: string[])
     throw new Error(`Kunde inte uppdatera produkt: ${text}`);
   }
 
+  const updatedProduct = await res.json();
+
   const tagsRes = await fetch(`${API_BASE}/api/products/${id}/tags`, {
     method: 'PUT',
     headers: { 'Content-Type': 'application/json', ...authHeaders },
@@ -108,6 +110,14 @@ export async function updateProductWithTags(formData: FormData, tags: string[])
     const text = await tagsRes.text();
     throw new Error(`Kunde inte uppdatera taggar: ${text}`);
   }
+
+  // Fetch the complete product (includes tags, categoryRef) after both updates
+  const fullRes = await fetch(`${API_BASE}/api/products/${id}`, {
+    headers: authHeaders,
+    cache: 'no-store',
+  });
+  if (!fullRes.ok) return updatedProduct;
+  return fullRes.json();
 }
 
 export async function deleteProduct(id: number) {