AmazonOA #10
MovieDB(MERN): Search Functionality
估计中等非算法题评测数据准备中，可先阅读题面
考点（AI 标注）字符串模拟/实现
修两个 bug:
- Basic search case-sensitive + only title (应 case-insensitive, 支持 title/celebs/all filter)
- Advanced search filter (year range / rating range / genre array / director / writer) 永远返回 No Matching Results
考点: Mongo $regex + $options: 'i', $and 复合 filter, decimal rating $gte/$lte.