test(e2e): take the mood empty state's add control in the managed-profile journey

Since an empty mood list carries the one add control and the header drops
its own, the journey clicked a header button that unmounted as the list
resolved. Start the profile without entries, assert the empty-state add,
then the header add once an entry exists. Both carry a data-slot.

src/components/mood/mood-list.tsx

@@ -742,7 +742,11 @@ export function MoodList({ onAddFirst, onEmptyChange }: MoodListProps = {}) {
                   {t("mood.emptyResetFilter")}
                 </Button>
               ) : onAddFirst && canManageMind ? (
-                <Button size="sm" onClick={onAddFirst}>
+                <Button
+                  size="sm"
+                  onClick={onAddFirst}
+                  data-slot="mood-add-first"
+                >
                   <Plus className="h-4 w-4" />
                   {t("mood.emptyAddFirst")}
                 </Button>