Nick Bosa returns to practice — why he just might be 49ers’ X-factor

SANTA CLARA — Fred Warner, check. Christian McCaffrey, check. George Kittle, check. And, at last, the 49ers can put a checkmark next to Nick Bosa’s name. The All-Pro pass rusher who hadn’t played since last September became the last of the Niners’ injured stars to return to practice Wednesday, just in the nick of time...