perf: 综合安全加固 — RBAC严格映射+异步邮件+字段权限白名单+前端对齐+导入模板

本次提交包含本会话所有修改的最终统一提交

## 权限系统重构
- permission_service.py: 添加入库/采购操作元素 + ensure_default_permissions
- field_permissions.py: 严格1-to-1 Default Deny 字段映射(StockBuy/Semi/Product/MaterialBase)
- decorators.py: _expand_operation_perms 双向粒度桥接 + prevent_double_submit
- deploy_production.sql: 修复 sys_element 别名码(qty_inbound→in_quantity)

## 采购模块
- purchase.py: 权限驱动可见性 + inbound_purchase独立权限 + 价格字段过滤
- purchase_service.py: 异步邮件 + 三阶段批量模糊匹配防N+1
- purchase/index.vue: canApprove严格操作权限 + upload重复修复

## 导出/入
- base_service.py: export_excel 流式写入防OOM + get_latest_specs 优化
- import_service.py + import_api.py: Excel批量导入（模板+预览+执行）
- ImportDialog.vue: 三步骤导入弹窗

## 异步邮件
- email_service.py: send_email_async (守护线程)
- inventory_task.py: send_email→send_email_async

## 前端对齐
- product/semi/buy.vue: 列对齐in_quantity/stock_quantity/available_quantity + localStorage缓存V2
- buyOdoo.vue: 排序修复 + 导入按钮 + 移除点击展开加载
- BomManage.vue: 懒加载分组 + 导入按钮
- list.vue: 导入按钮
- Selection.vue + borrow/apply: BOM匹配修复 + 导入按钮
- outbound/create.vue: 出库类型必选
- AppMain.vue: 移除transition白屏修复
- material_base.ts, outbound.ts, bom.ts, stock.ts: 新增API函数

db_migrations/deploy_production.sql

@@ -104,7 +104,11 @@ SELECT 'inbound_product', '质检报告链接(入库)', 'inbound_product:inspect
 INSERT INTO sys_element (menu_code, name, code, element_type)
 SELECT 'inbound_product', '详情链接',     'inbound_product:detail_link',           'column' WHERE NOT EXISTS (SELECT 1 FROM sys_element WHERE code = 'inbound_product:detail_link');
 INSERT INTO sys_element (menu_code, name, code, element_type)
-SELECT 'inbound_product', '入库数量',     'inbound_product:qty_inbound',           'column' WHERE NOT EXISTS (SELECT 1 FROM sys_element WHERE code = 'inbound_product:qty_inbound');
+SELECT 'inbound_product', '入库数量',     'inbound_product:in_quantity',           'column' WHERE NOT EXISTS (SELECT 1 FROM sys_element WHERE code = 'inbound_product:in_quantity');
+INSERT INTO sys_element (menu_code, name, code, element_type)
+SELECT 'inbound_product', '当前库存',     'inbound_product:stock_quantity',       'column' WHERE NOT EXISTS (SELECT 1 FROM sys_element WHERE code = 'inbound_product:stock_quantity');
+INSERT INTO sys_element (menu_code, name, code, element_type)
+SELECT 'inbound_product', '当前可用',     'inbound_product:available_quantity',   'column' WHERE NOT EXISTS (SELECT 1 FROM sys_element WHERE code = 'inbound_product:available_quantity');
 
 -- 2.2 BOM 管理字段权限（5个缺失码）
 INSERT INTO sys_element (menu_code, name, code, element_type)