1、GetCommodityStocksByStoreID优化，加锁解决concurrent map writes 的问题；

app/admin/models/purchase.go

@@ -2639,6 +2639,7 @@ func GetCommodityStocksByStoreID(commodityID uint32, stores []uint32) (map[uint3
 	wg.Add(len(stores))
 
 	result := make(map[uint32]uint32)
+	var mu sync.Mutex // 用于保护 `result`
 
 	for _, store := range stores {
 		go func(storeID uint32) {
@@ -2652,7 +2653,9 @@ func GetCommodityStocksByStoreID(commodityID uint32, stores []uint32) (map[uint3
 				// Handle error
 				return
 			}
+			mu.Lock() // 加锁
 			result[storeID] = uint32(stockCount)
+			mu.Unlock() // 解锁
 		}(store)
 	}