Lab 1: Tame the data drop

Your first day on the data team. A vendor sent a folder called drop with a mix of sales files, reference data, temporary leftovers, and a hidden credentials file. Before anyone loads it into the warehouse, it needs a clean, predictable structure:

drop/
├── raw/
│   ├── sales/   ← monthly sales CSVs
│   └── ref/     ← reference data (customers)
├── archive/     ← dated backups
└── README.txt

Every task uses commands from the lesson: pwd, cd, ls, mkdir, mv, cp, rm, rmdir, head, find. Tasks tick themselves when the files are in the right place, or when the right output appears in the terminal.