fix: aggressively serialize getAllProducts output to prevent React RSC stream errors

lib/mdx.ts

@@ -193,22 +193,28 @@ export async function getAllProducts(locale: string): Promise<ProductMdx[]> {
           .filter(Boolean);
         return resolvedImages.length > 0;
       })
-      .map((doc) => ({
-        slug: doc.slug,
-        frontmatter: {
-          title: doc.title,
-          sku: doc.sku || '',
-          description: doc.description || '',
-          categories: Array.isArray(doc.categories)
-            ? doc.categories.map((c: any) => c.category)
-            : [],
-          images: ((doc.images as any[]) || [])
-            .map((img) => (typeof img === 'string' ? img : img.url))
-            .filter(Boolean),
-          locale: doc.locale,
-        },
-        content: null,
-      }));
+      .map((doc) => {
+        const resolvedImages = ((doc.images as any[]) || [])
+          .map((img) => (typeof img === 'string' ? img : img.url))
+          .filter(Boolean) as string[];
+
+        const plainCategories = Array.isArray(doc.categories)
+          ? doc.categories.map((c: any) => String(c.category))
+          : [];
+
+        return {
+          slug: String(doc.slug),
+          frontmatter: {
+            title: String(doc.title),
+            sku: doc.sku ? String(doc.sku) : '',
+            description: doc.description ? String(doc.description) : '',
+            categories: plainCategories,
+            images: resolvedImages,
+            locale: String(doc.locale),
+          },
+          content: null,
+        };
+      });
 
     // Also include English fallbacks for slugs not in this locale
     if (locale !== 'en') {
@@ -229,23 +235,29 @@ export async function getAllProducts(locale: string): Promise<ProductMdx[]> {
             .filter(Boolean);
           return resolvedImages.length > 0;
         })
-        .map((doc) => ({
-          slug: doc.slug,
-          frontmatter: {
-            title: doc.title,
-            sku: doc.sku || '',
-            description: doc.description || '',
-            categories: Array.isArray(doc.categories)
-              ? doc.categories.map((c: any) => c.category)
-              : [],
-            images: ((doc.images as any[]) || [])
-              .map((img) => (typeof img === 'string' ? img : img.url))
-              .filter(Boolean),
-            locale: doc.locale,
-            isFallback: true,
-          },
-          content: null,
-        }));
+        .map((doc) => {
+          const resolvedImages = ((doc.images as any[]) || [])
+            .map((img) => (typeof img === 'string' ? img : img.url))
+            .filter(Boolean) as string[];
+
+          const plainCategories = Array.isArray(doc.categories)
+            ? doc.categories.map((c: any) => String(c.category))
+            : [];
+
+          return {
+            slug: String(doc.slug),
+            frontmatter: {
+              title: String(doc.title),
+              sku: doc.sku ? String(doc.sku) : '',
+              description: doc.description ? String(doc.description) : '',
+              categories: plainCategories,
+              images: resolvedImages,
+              locale: String(doc.locale),
+              isFallback: true,
+            },
+            content: null,
+          };
+        });
 
       products = [...products, ...fallbacks];
     }