handle nuclei in fluka::canInteract()

corsika/modules/fluka/ParticleConversion.hpp

@@ -44,6 +44,7 @@ namespace corsika::fluka {
   }
 
   bool const canInteract(Code const code) {
+    if (is_nucleus(code)) return false; // nuclei support not yet implemented
     return flukaCanInteract[static_cast<CodeIntType>(code)];
   }
 } // namespace corsika::fluka