feat(storefront): render product description as markdown

- Add react-markdown dependency to storefront
- Use ReactMarkdown in ProductDetailDescriptionSection for formatted descriptions

Made-with: Cursor

apps/storefront/src/components/product-detail/sections/ProductDetailDescriptionSection.tsx

@@ -1,11 +1,16 @@
+import ReactMarkdown from "react-markdown";
+
 type ProductDetailDescriptionSectionProps = {
-  /** Product description (HTML or plain text); server-rendered in initial HTML per SEO. */
+  /** Product description (Markdown); server-rendered in initial HTML per SEO. */
   description?: string | null;
 };
 
+const descriptionClasses =
+  "max-w-3xl text-sm leading-relaxed text-[var(--foreground)]/80 [&_ol]:mb-3 [&_ol]:list-inside [&_ol]:list-decimal [&_p:last-child]:mb-0 [&_p]:mb-3 [&_ul]:mb-3 [&_ul]:list-inside [&_ul]:list-disc";
+
 /**
  * Description content for the PDP tabs section.
- * Renders inside a parent <section> provided by ProductDetailTabsSection.
+ * Renders Markdown as HTML inside a parent <section> provided by ProductDetailTabsSection.
  * If empty, shows a short fallback message.
  */
 export function ProductDetailDescriptionSection({
@@ -15,10 +20,9 @@ export function ProductDetailDescriptionSection({
     typeof description === "string" && description.trim().length > 0;
 
   return hasContent ? (
-    <div
-      className="max-w-3xl text-sm leading-relaxed text-[var(--foreground)]/80 [&_ol]:mb-3 [&_ol]:list-inside [&_ol]:list-decimal [&_p:last-child]:mb-0 [&_p]:mb-3 [&_ul]:mb-3 [&_ul]:list-inside [&_ul]:list-disc"
-      dangerouslySetInnerHTML={{ __html: description!.trim() }}
-    />
+    <div className={descriptionClasses}>
+      <ReactMarkdown>{description!.trim()}</ReactMarkdown>
+    </div>
   ) : (
     <p className="text-sm text-[var(--muted)]">No description available.</p>
   );