feat(ECR-009): Ops-D order filters, plan display prices, refund status

LOOP-RUN-002 sample: admin order multi-filter, membership display
price catalog, read-only refund_status. No real payment or RBAC.

Co-authored-by: Cursor <cursoragent@cursor.com>

apps/api/migrations/000015_ops_commerce.down.sql

@@ -0,0 +1,4 @@
+DROP TABLE IF EXISTS membership_plan_prices;
+DROP INDEX IF EXISTS idx_orders_status_created;
+ALTER TABLE orders DROP CONSTRAINT IF EXISTS orders_refund_status_check;
+ALTER TABLE orders DROP COLUMN IF EXISTS refund_status;