v1.0.0 - season package discounts by distinct concert category

First release. Replaces the two Discount Rules (Flycart, free) rules that enumerated Adult product IDs and went stale silently when a performance was added - the defect that overcharged a real customer 176 dollars for a 160 dollar package on 2026-08-18 (order 7171). Counts distinct child terms of Season Concerts (86) instead, so three nights of one concert correctly count as one concert. Standalone: deactivating it is the entire rollback.