Cost a florist's event flower orders with stem wastage, whole bunches per event date, trade discounts and delivery

# Cost a florist's event flower orders with stem wastage, whole bunches per event date, trade discounts and delivery Inputs: `orders.csv` (order_id, client_id, event_date, arrangement, quantity), `recipes.json` (per arrangement: its price and the stems of each flower in one arrangement), `flowers.json` (per flower: bunch_size, bunch_price, waste_pct), `clients.csv` (client_id, name, tier) and `rates.json` (trade_pct, delivery_fee). All clients and orders are synthetic; amounts are in dollars. These rules are the studio's policy; where `studio-note.txt` disagrees, the rules win. Rules: - Stems: for each order and flower, stems = the recipe's stems × quantity, plus waste_pct of that for wastage, rounded up to a whole stem for that order on its own. - Bunches: flowers are bought per event date: for each event date and flower, bunches = the stems of all that date's orders ÷ bunch_size, rounded up to a whole bunch; the date's flower cost = the sum of bunches × bunch_price. - Pricing: order price = quantity × the arrangement's price; clients whose tier is 'trade' get trade_pct off the price (rounded half-up to the cent); a client pays delivery_fee once per event date, on their order with the lowest order_id that date, and 0 delivery on their other orders that date; order total = price − discount + delivery. - Write `out/costing.json`: `{"stems": {"<event_date>": {"<flower>": <stems>, ...}, ...}, "bunches": {"<event_date>": {"<flower>": <bunches>, ...}, ...}, "flower_cost": {"<event_date>": <dollars>, ...}, "orders": {"<order_id>": {"price": <dollars>, "discount": <dollars>, "delivery": <dollars>, "total": <dollars>}, ...}, "clients": {"<client_id>": <sum of the client's order totals>, ...}}`. `orders` has one entry per row of orders.csv. - Roll-ups: Flowers with no stems on an event date are left out of that date's stems and bunches. Event dates with no orders are left out. Clients in clients.csv with no orders are included at 0. ## How this run works - Work on your own: nobody will answer questions in this task, and writing to `ask/` counts against the run. - Write only under `out/`. Create `out/` if it is missing. Inputs are synthetic; don't fetch anything from the network. - Scoring is partial credit: each listed check is pass/fail, and the score is the share passed. Numbers are compared to within 0.005 unless the task says otherwise.