feat(hadis): filter root categories by default in CategoriesBySectView for accurate total counts

- Add is_root query param filter defaulting to true (parent__isnull=True) in CategoriesBySectView
- Ensure pagination count returns total count of root categories for the sect

apps/hadis/views/category.py

@@ -399,7 +399,17 @@ class CategoriesBySectView(ListAPIView):
 
     def get_queryset(self):
         sect_type = self.kwargs.get('sect_type')
-        return HadisCategory.objects.filter(sect__sect_type=sect_type)
+        queryset = HadisCategory.objects.filter(
+            sect__sect_type=sect_type,
+            sect__is_active=True
+        )
+        is_root = self.request.query_params.get('is_root', 'true').lower()
+        if is_root in ['true', '1']:
+            queryset = queryset.filter(parent__isnull=True)
+        elif is_root in ['false', '0']:
+            queryset = queryset.filter(parent__isnull=False)
+
+        return queryset.order_by('order', 'id')
 
     @categories_by_sect_swagger
     def get(self, request, *args, **kwargs):