            shared=D(output['shared_cost']);units=sum(r['units'] for r in data['kits']);rows=[]
            for kit in data['kits']:
                share=(shared*kit['units']/units).quantize(D('.01'));cost=D(kit['component_cost'])+share;profit=D(kit['revenue'])-cost
                rows.append({**kit,'packaging_allocated':money(share),'total_cost':money(cost),'profit':money(profit)})
            check('分摊总额等于唯一外箱成本',sum(D(r['packaging_allocated']) for r in rows)==shared);check('共享成本不重复整箱计入',[r['packaging_allocated'] for r in rows]==['2.00','4.00']);check('批次利润独立对总额',sum(D(r['profit']) for r in rows)==D('44.00'));cout('kit-margin.csv',rows);result={'kits':rows,'shared_cost':money(shared),'batch_profit':'44.00'}
