fix: update TenderDetailInfo type to include buyer metrics

frontend/lib/types.ts

@@ -130,6 +130,8 @@ export type TenderDetailInfo = {
     has_economic_docs?: boolean;
     question_count?: number;
     has_adjudication?: boolean;
+    buyer_complaints?: number;
+    buyer_purchases?: number;
   };
   error?: string;
 };