Write SQL for cold-complaint diagnostics with LAG/QUALIFY

This problem asks for a single SQL script written with CTEs in a BigQuery/Snowflake-style dialect. The reference date is 2025-10-01, and every timestamp is already stored in the corresponding city’s local timezone. Tables order_events.status can be 'ready', 'picked_up', or 'delivered'. Schema Sample Rows Business Rules Only rows where deliveries.status = 'completed' are considered. A valid cold complaint is one where complaints.type = 'cold' and complaints.complaint_ts falls…