fix: 修复减钱助力接口参数传递方式

将减钱助力查询和点击接口的参数由查询字符串改为请求体传递，以符合后端接口规范。同时修正前端减钱按钮显示条件，使用正确的字段 `canInvite` 判断。

api/modules/mall.js

@@ -81,10 +81,10 @@ export const useMallApi = (Vue, vm) => {
         getReduceQrcodeAjax: (params) => vm.$u.get('/token/shop/order/getReduceQrcode', params),
         
         // 减钱助力查询
-        reduceHelpQueryAjax: (reduceCode) => vm.$u.post('/token/shop/order/inviteHelpQuery?reduceCode=' + reduceCode),
+        reduceHelpQueryAjax: (reduceCode) => vm.$u.post('/token/shop/order/inviteHelpQuery', { reduceCode }),
         
         // 减钱助力点击
-        reduceClickHelpAjax: (data) => vm.$u.post('/token/shop/order/inviteClickHelp?reduceCode=' + data.reduceCode, data),
+        reduceClickHelpAjax: (data) => vm.$u.post('/token/shop/order/inviteClickHelp', data),
         
         // 减钱去分享
 		goToReduceShareAjax: (params) => vm.$u.get('/token/shop/order/goToShare', params),

pages-car/components/cart-item.vue

@@ -56,7 +56,7 @@
                 </view>
 
                 <!-- 去减钱按钮 -->
-                <view class="reduce-btn" v-if="canReduce" @click.stop="handleReduce">
+                <view class="reduce-btn" v-if="item.canInvite == 1" @click.stop="handleReduce">
                     <text>去减钱</text>
                 </view>