后台完成修复，初始化项目

src/main/resources/lua/cart_operation.lua

@@ -0,0 +1,50 @@
+-- 购物车操作Lua脚本
+-- 功能：原子性地更新购物车并检查库存
+-- 参数：KEYS[1] = 购物车key, KEYS[2] = 库存key, ARGV[1] = 商品ID, ARGV[2] = 数量, ARGV[3] = 操作类型(add/update/remove)
+-- 返回值：成功返回新数量，失败返回负数
+
+local cart_key = KEYS[1]
+local stock_key = KEYS[2]
+local product_id = ARGV[1]
+local quantity = tonumber(ARGV[2])
+local operation = ARGV[3]
+
+-- 获取当前库存
+local current_stock = redis.call('GET', stock_key)
+if current_stock == false then
+    return -1  -- 商品不存在
+end
+current_stock = tonumber(current_stock)
+
+-- 获取购物车中当前商品数量
+local cart_quantity = redis.call('HGET', cart_key, product_id)
+cart_quantity = cart_quantity and tonumber(cart_quantity) or 0
+
+local new_quantity = 0
+
+if operation == 'add' then
+    new_quantity = cart_quantity + quantity
+elseif operation == 'update' then
+    new_quantity = quantity
+elseif operation == 'remove' then
+    redis.call('HDEL', cart_key, product_id)
+    return 0
+else
+    return -2  -- 无效操作
+end
+
+-- 检查库存是否足够
+if new_quantity > current_stock then
+    return -3  -- 库存不足
+end
+
+-- 更新购物车
+if new_quantity > 0 then
+    redis.call('HSET', cart_key, product_id, new_quantity)
+    -- 设置购物车过期时间（7天）
+    redis.call('EXPIRE', cart_key, 7 * 24 * 3600)
+else
+    redis.call('HDEL', cart_key, product_id)
+end
+
+return new_quantity