Add SEO meta descriptions and a dynamic sitemap.

Expose optional metaDescription for blogs, reportages, and brands in admin/API, apply it on detail pages, and serve an up-to-date /sitemap.xml for approved content plus static site pages.

Co-authored-by: Cursor <cursoragent@cursor.com>

apps/api/prisma/schema.prisma

@@ -49,6 +49,7 @@ model Blog {
   title              String
   slug               String             @unique
   abstract           String?
+  metaDescription    String?
   content            String             @default("")
   imageUrl           String?
   tags               String[]           @default([])
@@ -80,6 +81,7 @@ model Reportage {
   slug               String             @unique
   businessOwner      String
   abstract           String?
+  metaDescription    String?
   content            String             @default("")
   imageUrl           String?
   tags               String[]           @default([])
@@ -110,6 +112,7 @@ model Brand {
   title              String
   slug               String             @unique
   abstract           String?
+  metaDescription    String?
   content            String             @default("")
   imageUrl           String?
   galleryUrls        String[]           @default([])