fix(service-detail): 修正派工时间字段取值逻辑

- 将派工时间数据源从 dispatchTime || applyTime 改为 repairDispatchTime
- 添加空值三元判断避免显示异常

pages/service-detail/service-detail.vue

@@ -29,7 +29,7 @@
 
                 <template v-if="infoData">
                     <equipment-line title="故障类别" :content="infoData.repairErrorTypeName" />
-                    <equipment-line title="派工时间" :content="infoData.dispatchTime || infoData.applyTime" />
+                    <equipment-line title="派工时间" :content="infoData.repairDispatchTime" />
                     <equipment-line title="维修开始" :content="infoData.repairActualStartTime || infoData.repairStartTime" />
                     <equipment-line title="维修结束" :content="infoData.repairEndTime" />
                     <equipment-line title="维修耗时" :content="repairDurationDisplay" />
@@ -118,7 +118,7 @@
                         <template v-slot:content>
                             <view>
                                 <view class="u-order-desc">派工时间</view>
-                                <view class="u-order-time">{{ (infoData.dispatchTime || infoData.applyTime) }}</view>
+                                <view class="u-order-time">{{ infoData.repairDispatchTime ? infoData.repairDispatchTime : '' }}</view>
                             </view>
                         </template>
                     </u-time-line-item>