The European Union is preparing to take a much bigger swing at Russia’s oil trade, and this time Brussels is aiming less at optics and more at the plumbing that actually keeps barrels moving. The European Commission has proposed what would be its broadest sanctions package yet against Russian crude exports, targeting not just ships or buyers but the services that make seaborne oil trade possible in the first place. The plan would ban European firms from providing shipping, insurance, financing, and other maritime services for Russian crude…