HONG KONG (BLOOMBERG) - Before the accounting scandal and the stock crash and the defaulted loans, Luckin Coffee's billionaire founder Lu Zhengyao was an ideal customer for Credit Suisse Group. "I've had I don't know how many dinners with him in Beijing and he's absolutely the poster child for what we want to do," Tidjane Thiam said at a conference last year when he was still head of the bank. He lauded Lu's relationship with the firm that ranged from private banking to stock sales. "He's a dream client." Luckin's dramatic fall from grace this month blindsid...