feat: 结算单列表新增金蝶冲销状态（定时回写+预检/重推实时回写）

- 正式结算单表新增 kingdee_writeoff_status/kingdee_writeoff_time 字段（可重复执行DDL）
- A102-4/A302-4 新增冲销标志批量查询，原单键冲销查询复用批量
- 金蝶结果定时任务新增子流程④：已同步结算单冲销状态批量回写（single-flight 锁）
- 结算调整选单预检、重推硬闸门实时查询后顺带回写单笔冲销状态

doc/sql/transport/lqj/temp/06_blade_formal_settlement_kingdee_writeoff_20261030.sql

@@ -0,0 +1,31 @@
+-- 正式结算单：新增金蝶冲销状态字段
+-- 结算单列表展示金蝶侧旧应付/应收单冲销状态：定时任务按 A102-4/A302-4 hadwrittenoff 批量回写，
+-- 选单预检/重推闸门实时查询后顺带回写；NULL=未推送金蝶或尚未校验，unwrittenoff-未冲销，writtenoff-已冲销（部分冲销视同已冲销）
+
+-- 以下结构升级支持重复执行
+SET @ddl_sql = (
+  SELECT IF(COUNT(*) = 0,
+    'ALTER TABLE `blade_formal_settlement` ADD COLUMN `kingdee_writeoff_status` varchar(20) COLLATE utf8mb4_general_ci DEFAULT NULL COMMENT ''金蝶冲销状态：unwrittenoff-未冲销 writtenoff-已冲销（NULL=未推送金蝶或未校验）'' AFTER `kingdee_fail_reason`',
+    'SELECT 1')
+  FROM information_schema.COLUMNS
+  WHERE TABLE_SCHEMA = DATABASE()
+    AND TABLE_NAME = 'blade_formal_settlement'
+    AND COLUMN_NAME = 'kingdee_writeoff_status'
+);
+PREPARE ddl_stmt FROM @ddl_sql;
+EXECUTE ddl_stmt;
+DEALLOCATE PREPARE ddl_stmt;
+
+-- 以下结构升级支持重复执行
+SET @ddl_sql = (
+  SELECT IF(COUNT(*) = 0,
+    'ALTER TABLE `blade_formal_settlement` ADD COLUMN `kingdee_writeoff_time` datetime DEFAULT NULL COMMENT ''金蝶冲销状态确认时间（定时回写/预检回写时间）'' AFTER `kingdee_writeoff_status`',
+    'SELECT 1')
+  FROM information_schema.COLUMNS
+  WHERE TABLE_SCHEMA = DATABASE()
+    AND TABLE_NAME = 'blade_formal_settlement'
+    AND COLUMN_NAME = 'kingdee_writeoff_time'
+);
+PREPARE ddl_stmt FROM @ddl_sql;
+EXECUTE ddl_stmt;
+DEALLOCATE PREPARE ddl_stmt;