feat: 归档旧迁移文件，创建初始化数据迁移和重置脚本

migrations/archive/backfill_order_purchase_role.sql

@@ -0,0 +1,43 @@
+-- 数据回填脚本：为历史订单填充 purchase_role 和 operator_type
+-- 用途：将现有平台代购订单标记为 purchased_by_platform
+-- 执行时间：预计 < 1 秒（取决于历史订单数量）
+-- 回滚方法：将 purchase_role 和 operator_type 设为 NULL
+
+BEGIN;
+
+-- 1. 回填平台代购订单（offline + is_purchase_on_behalf = true）
+UPDATE tb_order
+SET
+    purchase_role = 'purchased_by_platform',
+    operator_type = 'platform'
+WHERE
+    payment_method = 'offline'
+    AND is_purchase_on_behalf = true
+    AND purchase_role IS NULL;
+
+-- 2. 显示回填统计信息
+DO $$
+DECLARE
+    updated_count INTEGER;
+BEGIN
+    SELECT COUNT(*) INTO updated_count
+    FROM tb_order
+    WHERE purchase_role = 'purchased_by_platform'
+      AND operator_type = 'platform';
+
+    RAISE NOTICE '已回填 % 条平台代购订单', updated_count;
+END $$;
+
+COMMIT;
+
+-- 验证回填结果
+SELECT
+    purchase_role,
+    operator_type,
+    payment_method,
+    is_purchase_on_behalf,
+    COUNT(*) as count
+FROM tb_order
+WHERE purchase_role IS NOT NULL
+GROUP BY purchase_role, operator_type, payment_method, is_purchase_on_behalf
+ORDER BY count DESC;