feat(wms): 添加第二个表格统计功能

- 在 IWmsRawMaterialService 中新增 queryStatistics 方法用于统计原材料数据
- 在 WmsRawMaterialController 中添加 /statistics 接口端点
- 在 WmsRawMaterialMapper 中新增 selectStatistics 查询方法
- 在 XML 映射文件中实现统计查询的 SQL 语句
- 在服务实现类中完成统计逻辑，按厂家、材质、规格分组计算钢卷件数和重量
- 新增 ManufacturerStatisticsVo、MaterialStatisticsVo、SpecificationStatisticsVo 和 WmsRawMaterialStatisticsVo 数据传输对象
- 实现多层级数据聚合统计功能，包括厂家、材质、规格维度的数据汇总

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

@@ -43,4 +43,20 @@ PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
         <result property="zincLayer" column="zinc_layer"/>
     </resultMap>
 
+    <select id="selectStatistics" resultType="com.klp.domain.vo.dashboard.WmsRawMaterialStatisticsVo">
+        SELECT
+            rm.manufacturer,
+            rm.material,
+            rm.specification,
+            COUNT(mc.coil_id) AS coilCount,
+            COALESCE(SUM(mc.net_weight), 0) AS totalWeight
+        FROM wms_raw_material rm
+        LEFT JOIN wms_material_coil mc ON rm.raw_material_id = mc.item_id
+            AND mc.item_type = 'raw_material'
+            AND mc.del_flag = 0
+        WHERE rm.del_flag = 0
+        GROUP BY rm.manufacturer, rm.material, rm.specification
+        ORDER BY rm.manufacturer, rm.material, rm.specification
+    </select>
+
 </mapper>