feat(换货): AUG26-005 换货业务数据迁移状态与失败恢复

- 新增成对迁移 000222：tb_exchange_order 增加非空 migration_status 与
  migration_failure_reason，按既有 migrate_data/migration_completed 回填历史，
  并加四值 CHECK 约束，不新增索引
- 模型与常量定义四种迁移状态及中文名称，保留既有布尔字段兼容语义
- 物流换货创建恒 not_migrated，发货按请求落 pending/not_migrated，
  完成成功写 migrated/not_migrated 并清空失败原因、同步兼容字段
- 直接换货创建即完成，任一步失败整体回滚，不持久化换货单、不产生 failed
- 迁移失败回滚全部业务修改后，在独立短事务内条件更新 failed 与安全失败原因
  并写失败审计，RowsAffected 为 0 时跳过状态写入但仍写审计
- failed 物流单重试仅限超级管理员或平台用户，授权以锁内 FOR UPDATE 判定为准，
  重试从钱包余额起整表重跑；非 failed 单沿用既有完成门禁
- 列表与详情返回迁移状态与中文名称，仅 failed 返回失败原因；既有三字段保持兼容
- 换货导出在「状态」列后新增中文「迁移状态」列，不导出失败原因
- 同步 order-refund-exchange 主 spec 与验证证据，归档本 Change
- 登记 KNOWN-ISSUE-001：既有标签复制 OnConflict 未声明部分索引谓词（42P10），
  旧资产带标签时迁移最后一步失败，待另立变更修复

docs/verification/context-reset/entry-capability-requirement-matrix.json

@@ -711,7 +711,8 @@
     "capability": "order-refund-exchange",
     "requirements": [
       "identity-access::数据范围拒绝",
-      "order-refund-exchange::订单、退款与换货状态门禁"
+      "order-refund-exchange::订单、退款与换货状态门禁",
+      "order-refund-exchange::换货业务数据迁移状态与失败恢复"
     ],
     "classification": "behavior"
   },
@@ -721,7 +722,8 @@
     "capability": "order-refund-exchange",
     "requirements": [
       "identity-access::数据范围拒绝",
-      "order-refund-exchange::订单、退款与换货状态门禁"
+      "order-refund-exchange::订单、退款与换货状态门禁",
+      "order-refund-exchange::换货业务数据迁移状态与失败恢复"
     ],
     "classification": "behavior"
   },
@@ -2077,7 +2079,8 @@
     "capability": "order-refund-exchange",
     "requirements": [
       "identity-access::数据范围拒绝",
-      "order-refund-exchange::订单、退款与换货状态门禁"
+      "order-refund-exchange::订单、退款与换货状态门禁",
+      "order-refund-exchange::换货业务数据迁移状态与失败恢复"
     ],
     "classification": "behavior"
   },
@@ -2097,7 +2100,9 @@
     "capability": "order-refund-exchange",
     "requirements": [
       "identity-access::数据范围拒绝",
-      "order-refund-exchange::订单、退款与换货状态门禁"
+      "order-refund-exchange::订单、退款与换货状态门禁",
+      "order-refund-exchange::换货业务数据迁移状态与失败恢复",
+      "order-refund-exchange::换货业务数据迁移范围"
     ],
     "classification": "behavior"
   },
@@ -2117,7 +2122,8 @@
     "capability": "order-refund-exchange",
     "requirements": [
       "identity-access::数据范围拒绝",
-      "order-refund-exchange::订单、退款与换货状态门禁"
+      "order-refund-exchange::订单、退款与换货状态门禁",
+      "order-refund-exchange::换货业务数据迁移状态与失败恢复"
     ],
     "classification": "behavior"
   },
@@ -2136,7 +2142,8 @@
     "capability": "export-task",
     "requirements": [
       "export-task::导出任务终态",
-      "identity-access::数据范围拒绝"
+      "identity-access::数据范围拒绝",
+      "order-refund-exchange::换货导出业务数据迁移状态"
     ],
     "classification": "behavior"
   },