Rasmus Dahlin doesn’t recall being this excited on NHL trade deadline day. Having endured only losing during his previous seven seasons in Buffalo, the Sabres captain was practically giddy — “I’m fired up,” he said after practice Friday — about the team adding rather than unloading talent to what’s become a bona fide playoff contender. Buffalo entered the day tied with Tampa Bay atop the Atlantic Division standings and added depth to strengthen its playoff run.