fix(api): update-stocktake-quantity 按 session_id 隔离更新，防止跨会话误改

后端 update_stocktake_quantity 原只按 stock_id+source_table 查草稿，
不同盘点会话会相互覆盖实盘数。后端增加 session_id 过滤，
前端 handleQuantityChange 配套传入当前会话ID，API 类型同步补全。

inventory-backend/app/api/v1/inbound/stock.py

@@ -1741,16 +1741,20 @@ def update_stocktake_quantity():
         data = request.json
         stock_id = data.get('stock_id')
         source_table = data.get('source_table')
+        session_id = data.get('session_id')  # ★ 修复：按会话隔离，防止跨会话误改
         quantity = float(data.get('quantity', 0))
-        
+
         if not stock_id or not source_table:
             return jsonify({'code': 400, 'msg': '缺少必要参数'}), 400
-        
-        # 查找对应的盘点记录
-        draft = StocktakeDraft.query.filter_by(
+
+        # 查找对应的盘点记录（★ 修复：限定 session_id，避免不同盘点会话相互覆盖）
+        query = StocktakeDraft.query.filter_by(
             stock_id=stock_id,
             source_table=source_table
-        ).first()
+        )
+        if session_id:
+            query = query.filter_by(session_id=session_id)
+        draft = query.first()
         
         if not draft:
             return jsonify({'code': 404, 'msg': '未找到盘点记录'}), 404

inventory-web/src/api/inbound/stock.ts

@@ -107,7 +107,7 @@ export function getAllStocktakeItems(params?: { keyword?: string; session_id?: s
 }
 
 // 更新盘点实盘数（手动修改）
-export function updateStocktakeQuantity(data: { stock_id: number; source_table: string; quantity: number }) {
+export function updateStocktakeQuantity(data: { stock_id: number; source_table: string; quantity: number; session_id?: string }) {
     return request({
         url: '/v1/inbound/stock/stocktake/update-quantity',
         method: 'post',

inventory-web/src/views/stock/stocktake/index.vue

@@ -1102,7 +1102,8 @@ const handleQuantityChange = async (row: any, val: number) => {
     await updateStocktakeQuantity({
       stock_id: row.stock_id,
       source_table: row.source_table,
-      quantity: val
+      quantity: val,
+      session_id: currentSessionId.value  // ★ 传入会话ID，后端按会话隔离更新
     })
     ElMessage.success('实盘数已更新')
   } catch (e) {