A contentious proposal to boycott Israeli products at the Park Slope Food Coop is roiling a liberal Brooklyn community and exposing a deepening divide across NYC, even spilling into the NY-10th District congressional primary between Democrats Rep. Dan Goldman and challenger Brad Lander.Members of the co-op are set to vote Tuesday on a heavily-debated proposal to ban all made-in-Israel items, with members staking out sides on both sides of the measure. Supporters say the ban would amount to a small but potent gesture of opposition to Israel’s policies in the Gaza and Iran wars and discrimination against the Palestinians. They...