The finance team wants to compare stores based on their average revenue per trading day.
A trading day is any calendar day on which a store receives at least one paid order, based on order_ts. Daily revenue comes from paid orders only.
Orders without a recorded amount_usd still count toward trading days but contribute nothing to revenue. If all paid orders for a store have missing amounts, its total revenue should be 0. Stores without any paid orders should not appear.
Prepare a store-level report showing the number of trading days, total revenue, and average revenue per trading day.
Ordering: Sort by avg_daily_revenue from highest to lowest. If stores have the same average, the smaller store_id comes first.