PHILADELPHIA — So much of the joy in sports is based on the expectations that precede a celebration, on the circumstances in which an accomplishment is achieved. So here were the Washington Capitals — not those old Stanley Cup-contending Washington Capitals but a different version with a new reality — gathered in a grinning group on the ice at Wells Fargo Center. They vigorously patted each other on the heads, gloves knocking helmets around. And then, with a playoff berth locked up, they bounced as one, a circle of glee following a season of unspeakable grind.