Record a note about the last hash-set.

dw/types.hh

@@ -266,6 +266,10 @@ struct Content
 class StackingProcessingContext
 {
 private:
+   // This hash-set "owns" a bunch of entities that are passed to it via raw pointer form.
+   // But the entities seem to be passed in as `this` from the object itself.
+   //
+   // I'm delaying untangling that ownership thicket.
    lout::container::typed::HashSet<lout::object::TypedPointer<Widget> >
       *widgetsProcessedAsInterruption;