Confusion over Thailand’s new coronavirus curbs left travellers scrambling on Friday as Thai citizens queued at embassies abroad to get special travel papers and foreigners faced the challenge of producing a negative test for the disease.Testing kits are limited in most countries, especially to people who appear healthy – meaning the Thai rules amount to a de facto ban on all foreigners.The regulations, which take effect on Sunday, were announced on Thursday, but a clarifying document from the…