All summer long, one massive series kept looming on the schedule. Three games between the Mets and Braves in Atlanta during the final week of the season. With the NL East rivals locked in a heated wild-card race, surely it would come down to their head-to-head matchup. And here we are. If the banged-up Braves are going to earn a seventh straight playoff berth, they’ll need a big performance at home. If the surprising Mets are going to finish this postseason push, they can do it by toppling a familiar nemesis. On the line at Truist Park beginning Tuesday night — nothing less than a chance to play in October.