Modified TenderDetailHeader to conditionally display the estimated value container based on its presence

lib/views/detail/widgets/tender_detail_header.dart

@@ -199,7 +199,9 @@ class TenderDetailHeader extends StatelessWidget {
             ? Flag(countryCode: detail.countryCode!)
             : const Flag(countryCode: ''),
         const Spacer(),
-        Container(
+        Visibility(
+          visible: detail.estimatedValue != null && detail.estimatedValue != 0,
+          child: Container(
             height: 32.0.h(),
             padding: EdgeInsets.symmetric(horizontal: 16.0.w()),
             decoration: BoxDecoration(
@@ -216,6 +218,7 @@ class TenderDetailHeader extends StatelessWidget {
               ),
             ),
           ),
+        ),
       ],
     );
   }