PARIS — The Louvre Museum must spend on safety and security instead of flash, a new report from France’s top court of auditors said, casting doubts on French President Emmanuel Macron’s billion-euro plan to build a new entrance for the museum and give Leonardo da Vinci’s “Mona Lisa” its own room. The report, released Thursday, had been widely expected after a spectacular heist last month in which €88 million of jewelry once belonging to French royal and imperial families was stolen from the