Pro warehouses only. This table is not delivered on Foundation warehouses. See Foundation and Pro.
- Grain: One row per sm_order_discount_key. No canonical date; _synced_at is a freshness timestamp (not for analysis).
- Filters to start with: source_system for platform-specific discount representation.
- Joins: dim_order_lines via sm_order_line_key (many:1); dim_orders via sm_order_key (many:1).

