perf: 系统级性能优化与并发安全修复

## 并发安全修复 (4处)
- scrap.py: 报废执行添加 SELECT FOR UPDATE 悲观锁，消除 TOCTOU 竞态
- stock.py (adjust_stock): 盘点调整添加 for_update=True 行锁
- outbound_service.py: 低库存预警 SMTP 调用移到 commit 之后，避免长事务
- trans_service.py: execute_dispatch 按 (source_table, id) 排序 items，消除死锁风险

## N+1 查询优化 (2处)
- inventory_task.py: _prefetch_inventory_map 单条 UNION ALL+GROUP BY 替代循环内逐条查询（N*4次→2次）
- stock.py (export_stocktake): get_borrowed_qty 批量 GROUP BY 替代逐条 TransBorrow 查询（~18000次→1次）

## BOM 列表性能重构
- bom_service.py: get_bom_list 单条 GROUP BY+string_agg+分页，消除 N+1 循环查询
- bom_service.py: 新增 get_bom_summary (轻量 GROUP BY category+COUNT)
- bom.py: 新增 /api/v1/bom/summary 路由，/list 支持 category 过滤

## Odoo 基础信息懒加载
- base_service.py: 新增 get_odoo_summary (GROUP BY category+COUNT)
- base.py: 新增 /api/v1/inbound/base/odoo-summary 路由
- buyOdoo.vue: 懒加载分组架构 (fetchOdooSummary + loadGroupItems)
- material_base.ts: 新增 getOdooSummary API

## 前端 Bug 修复
- BomManage.vue: 懒加载分组 (fetchBomSummary + loadGroupItems + collapse)
- BomManage.vue: 适配新 API 格式 (res.data.items 替代 res.data)
- buyOdoo.vue: 移除 "点击展开加载" 文字
- Selection.vue + borrow/apply/index.vue: openBomSelect 适配新 API 格式

inventory-backend/app/services/inbound/base_service.py

@@ -476,6 +476,62 @@ class MaterialBaseService:
             print(f"查询基础信息列表失败: {e}")
             return {"total": 0, "items": []}
 
+    @staticmethod
+    def get_odoo_summary(keyword=None, is_enabled=None):
+        """
+        Odoo 分组摘要 API（极轻量，不 JOIN 任何库存表）
+
+        执行:
+            SELECT category, COUNT(id) AS count
+            FROM material_base
+            WHERE ...
+            GROUP BY category
+            ORDER BY category
+
+        返回:
+            [{"category": "IRIS/半成品/高塔监测T", "count": 54}, ...]
+        """
+        try:
+            query = db.session.query(
+                MaterialBase.category,
+                func.count(MaterialBase.id).label('count')
+            )
+
+            # 状态过滤
+            if is_enabled is not None:
+                query = query.filter(MaterialBase.is_enabled == is_enabled)
+
+            # 关键词搜索（与 get_list 行为一致）
+            if keyword:
+                kw = f'%{keyword.strip()}%'
+                query = query.filter(or_(
+                    MaterialBase.name.ilike(kw),
+                    MaterialBase.common_name.ilike(kw),
+                    MaterialBase.spec_model.ilike(kw)
+                ))
+
+            # 行级数据隔离
+            from app.utils.decorators import get_current_company_filter
+            company_limit = get_current_company_filter()
+            if company_limit is not None:
+                query = query.filter(MaterialBase.company_name == company_limit)
+
+            # GROUP BY + ORDER
+            query = query.group_by(MaterialBase.category) \
+                         .order_by(MaterialBase.category)
+
+            rows = query.all()
+
+            return [
+                {"category": row.category or "未分类", "count": row.count}
+                for row in rows
+            ]
+
+        except Exception as e:
+            traceback.print_exc()
+            print(f"查询 Odoo 摘要失败: {e}")
+            return []
+
     @staticmethod
     def get_distinct_options():
         """