style(health): 将删除按钮文字改为叉号图标

- 修改血糖记录页面的删除按钮显示为✕
- 修改血压记录页面的删除按钮显示为✕
- 修改心率记录页面的删除按钮显示为✕
- 修改体重记录页面的删除按钮显示为✕

src/pages/health/details/blood-glucose.vue

@@ -26,7 +26,7 @@
         <view v-for="item in records" :key="item.id" class="list-item">
           <view class="date">{{ item.date }}</view>
           <view class="value">{{ item.value }} mmol/L · {{ item.type }}</view>
-          <button class="btn-delete" @click="confirmDeleteRecord(item.id)">删除</button>
+          <button class="btn-delete" @click="confirmDeleteRecord(item.id)">✕</button>
         </view>
       </view>
     </view>

src/pages/health/details/blood-pressure.vue

@@ -26,7 +26,7 @@
         <view v-for="item in records" :key="item.id" class="list-item">
           <view class="date">{{ item.date }}</view>
           <view class="value">{{ item.s }}/{{ item.d }} mmHg</view>
-          <button class="btn-delete" @click="confirmDeleteRecord(item.id)">删除</button>
+          <button class="btn-delete" @click="confirmDeleteRecord(item.id)">✕</button>
         </view>
       </view>
     </view>

src/pages/health/details/heart-rate.vue

@@ -26,7 +26,7 @@
         <view v-for="item in records" :key="item.id" class="list-item">
           <view class="date">{{ item.date }}</view>
           <view class="value">{{ item.hr }} bpm</view>
-          <button class="btn-delete" @click="confirmDeleteRecord(item.id)">删除</button>
+          <button class="btn-delete" @click="confirmDeleteRecord(item.id)">✕</button>
         </view>
       </view>
     </view>

src/pages/health/details/weight.vue

@@ -27,7 +27,7 @@
         <view v-for="item in records" :key="item.id" class="list-item">
           <view class="date">{{ item.date }}</view>
           <view class="value">{{ item.weight }} kg</view>
-          <button class="btn-delete" @click="confirmDeleteRecord(item.id)">删除</button>
+          <button class="btn-delete" @click="confirmDeleteRecord(item.id)">✕</button>
         </view>
       </view>
     </view>