Eight-foot piles of rat-infested trash are choking the streets around Gracie Mansion — which has gotten white-glove shoveling treatment as Mayor Zohran Mamdani crows he can’t “imagine how it could get better’’ in the city. While Hizzoner’s Upper East Side neighbors are forced to trudge through garbage-plagued roads, roaming rodents and mounds of snow tainted with dog pee a full week after Winter Storm Fern, the sidewalks outside the lefty mayor’s digs on East 88th Street are squeaky clean. “Clean as a whistle for the mayor,” Rivers said. “Look at this side.” “This side” is marred by massive piles of...