Eighty countries jointly called Sunday for the “territorial integrity” of Ukraine to be the basis for any peace agreement to end Russia’s two-year war, though some key developing nations at a Swiss conference did not join in. The joint communique capped a two-day conference at the Bürgenstock resort in Switzerland marked by the absence of Russia, which was not invited, but that many attendees hoped could join in on a roadmap to peace. About 100 delegations, mostly Western countries but also some key developing nations, were on hand for the conference — and experts were on watch to see how and …