feat(wms/material-coil): 优化钢卷囤积统计查询性能

1. 重构囤积统计方法：将原Java循环计算逻辑替换为单SQL聚合查询，通过JSON_EXTRACT解析二维码步骤创建时间，一次性计算平均囤积周期与成本
2. 移除原低效实现：删除getHoardingStatistics方法中的批量查询与循环解析代码，消除N+1性能问题
3. 新增Mapper方法与XML映射：添加selectHoardingStatistics接口及对应SQL，支持与分页查询相同的条件筛选

调整前，统计需先查询钢卷列表再批量获取二维码并循环解析，存在性能瓶颈；调整后，通过单SQL完成所有聚合计算，大幅提升查询效率，支持大规模数据统计。

klp-wms/src/main/resources/mapper/klp/WmsMaterialCoilMapper.xml

@@ -984,6 +984,39 @@ PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
         ${ew.customSqlSegment}
     </select>
 
+    <!-- 统计已发货钢卷的囤积周期和囤积成本：在selectStatistics基础上JOIN二维码表，解析steps[0].create_time -->
+    <select id="selectHoardingStatistics" resultType="java.util.Map">
+        SELECT
+            COUNT(*) AS total_count,
+            ROUND(AVG(hoarding_seconds / 86400), 2) AS avg_hoarding_days,
+            ROUND(AVG(hoarding_seconds / 86400 * net_weight), 2) AS avg_hoarding_cost
+        FROM (
+            SELECT
+                IFNULL(mc.net_weight, 0) AS net_weight,
+                TIMESTAMPDIFF(SECOND,
+                    FROM_UNIXTIME(JSON_EXTRACT(wgr.content, '$.steps[0].create_time') / 1000),
+                    COALESCE(mc.export_time, mc.update_time)
+                ) AS hoarding_seconds
+            FROM wms_material_coil mc
+            INNER JOIN wms_generate_record wgr ON mc.qrcode_record_id = wgr.record_id
+                AND JSON_EXTRACT(wgr.content, '$.steps[0].create_time') IS NOT NULL
+            LEFT JOIN wms_warehouse w ON mc.warehouse_id = w.warehouse_id
+            LEFT JOIN wms_warehouse nw ON mc.next_warehouse_id = nw.warehouse_id
+            LEFT JOIN wms_actual_warehouse aw ON mc.actual_warehouse_id = aw.actual_warehouse_id
+            LEFT JOIN sys_user su ON mc.sale_id = su.user_id
+            LEFT JOIN wms_raw_material rm ON mc.item_type = 'raw_material' AND mc.item_id = rm.raw_material_id
+            LEFT JOIN wms_product p ON mc.item_type = 'product' AND mc.item_id = p.product_id
+            LEFT JOIN (
+                SELECT coil_id, COUNT(*) AS abnormal_count
+                FROM wms_coil_abnormal
+                WHERE del_flag = 0
+                GROUP BY coil_id
+            ) ca ON mc.coil_id = ca.coil_id
+            ${ew.customSqlSegment}
+        ) t
+        WHERE t.hoarding_seconds > 0
+    </select>
+
     <!-- 统计仓库使用次数（按warehouse_id出现次数排序） -->
     <select id="selectWarehouseIdCount" resultType="java.util.Map">
         SELECT warehouse_id, COUNT(*) AS coil_count