fix: 更新优惠券详情页的显示和兑换逻辑

将积分显示改为直接显示优惠券标题，并修改兑换提示语为核销操作

@@ -11,9 +11,8 @@
             <!-- Points and Title -->
             <view class="text-center mb-8">
                 <view class="text-4xl font-bold text-blue-500 mb-2">
-                    <text class="text-2xl">{{ reward.points }} 积分</text>
+                    <text class="text-2xl">{{ reward.title }}</text>
                 </view>
-                <h1 class="text-xl font-bold">{{ reward.title }}</h1>
             </view>
 
             <!-- Details Sections -->
@@ -95,16 +94,16 @@ const reward = ref({
 const handleRedeem = () => {
     // Show a confirmation modal
     Taro.showModal({
-        title: '确认兑换',
-        content: `将消耗 ${reward.value.points} 积分兑换此优惠券，是否确认？`,
+        title: '温馨提示',
+        content: `将核销此优惠券，是否确认？`,
         success: (res) => {
             if (res.confirm) {
                 // Simulate API call for redemption
-                Taro.showLoading({ title: '兑换中...' });
+                Taro.showLoading({ title: '核销中...' });
                 setTimeout(() => {
                     Taro.hideLoading();
                     Taro.showToast({
-                        title: '兑换成功',
+                        title: '核销成功',
                         icon: 'success',
                         duration: 2000
                     });