With Kharg Island, Iran’s main oil-export terminal, in flames after Saturday’s US-led attack , China’s energy lifeline is going up in smoke. Ignoring international sanctions, oil-thirsty China had long been the Ayatollah Khamenei regime’s main buyer .   To be sure, China was a cheap customer, paying well below the going market price for Iran’s bootleg oil.   Not only that, it insisted in paying in Chinese  yuan , not dollars, ensuring the money would flow back to China.    Beijing’s slick sales