The customer-success team wants to know how long each customer has been registered, measured in whole calendar days.
The customers table stores registration timestamps in signup_ts. Calculate tenure as of June 15, 2026, using the date the customer signed up and ignoring their signup time. For example, someone who signed up on June 14 has a tenure of 1 day on June 15, even if fewer than 24 hours have passed.
Ordering: Sort by customer_id in ascending order.