fix(tenders): correct cursor pagination and language query handling

Stop double-counting cursor stack depth so tender list pages advance sequentially, and only pass a language to tender details when lang is present in the URL.

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

src/app/tenders/[details]/page.tsx

@@ -29,9 +29,7 @@ interface IProps {
 // Backend has shipped the documents payload as a bare array, an `ApiResponse`
 // wrapper, and a `{ data: { documents: [...] } }` wrapper at different times.
 // Normalize so a real list is never dropped because of a wrapper mismatch.
-function extractTenderDocuments(
-  payload: unknown,
-): TTenderDocumentsResponse[] {
+function extractTenderDocuments(payload: unknown): TTenderDocumentsResponse[] {
   if (!payload) return [];
   if (Array.isArray(payload)) return payload as TTenderDocumentsResponse[];
 
@@ -58,12 +56,12 @@ const TenderDetails = ({ params }: IProps) => {
   const router = useRouter();
   const pathname = usePathname();
   const searchParams = useSearchParams();
-  const selectedLanguage = searchParams.get("lang") || "en";
+  const selectedLanguage = searchParams.get("lang") ?? "";
   const { mutate: translateTender, isPending: isTranslating } =
     useTranslateTenderMutation();
   const { data, isLoading, isError, isFetching } = useTenderDetailQuery(
     details,
-    { language: selectedLanguage },
+    selectedLanguage ? { language: selectedLanguage } : undefined,
   );
 
   const breadcrumbItems = [
@@ -107,7 +105,7 @@ const TenderDetails = ({ params }: IProps) => {
       const nextLanguage = event.target.value;
       if (!nextLanguage) return;
 
-      const prevLanguage = searchParams.get("lang") || "en";
+      const prevLanguage = searchParams.get("lang") ?? "";
       if (nextLanguage === prevLanguage) return;
 
       userPendingLangRef.current = nextLanguage;

src/hooks/useHybridPagination.ts

@@ -80,7 +80,7 @@ export const useHybridPagination = ({
 
     if (cursorStack.length > 0) {
       const last = cursorStack[cursorStack.length - 1];
-      return Math.max(0, last.fromPage - 1 + cursorStack.length);
+      return Math.max(0, last.fromPage);
     }
 
     const paramsCursor =