德國商法 貨櫃運送 船舶適航性 貨物照管義務 強制責任期間舉證責任 海牙規則 海牙威士比規則 漢堡規則 海上貨物運送法 German Commercial Code Container transport Seaworthiness Duty of care for cargo Period of compulsive liability Burden of proof Hague rules Hague-visby rules Hamburg rules Transport of goods by sea act