修复讲解页返回导航问题

- 移除讲解选择页外层重复返回按钮
- 业务单元列表返回时优先回到讲解展厅列表
- 兼容从首页讲解入口直接进入业务单元列表的页面栈

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/pages/explain/business-unit-list.vue

@@ -0,0 +1,134 @@
+<template>
+  <GuidePageFrame
+    active-tab="explain"
+    variant="static"
+    :show-top-tabs="false"
+    @tab-change="handleTopTabChange"
+    @back="handleBack"
+  >
+    <view class="explain-business-unit-page">
+      <ExplainHallSelect
+        :business-units="explainBusinessUnitItems"
+        stage="unit"
+        :selected-hall-name="selectedExplainHallName"
+        :loading="explainLoading"
+        :error="explainError"
+        @business-unit-click="handleExplainBusinessUnitClick"
+        @back="handleBack"
+      />
+    </view>
+  </GuidePageFrame>
+</template>
+
+<script setup lang="ts">
+import { computed, ref } from 'vue'
+import { onLoad } from '@dcloudio/uni-app'
+import GuidePageFrame from '@/components/navigation/GuidePageFrame.vue'
+import ExplainHallSelect, {
+  type ExplainBusinessUnitSelectItem
+} from '@/components/explain/ExplainHallSelect.vue'
+import {
+  explainUseCase
+} from '@/usecases/explainUseCase'
+import type {
+  ExplainBusinessUnit
+} from '@/domain/museum'
+import {
+  navigateToGuideTopTab,
+  type GuideTopTab
+} from '@/utils/guideTopTabs'
+
+const selectedExplainHallId = ref('')
+const selectedExplainHallName = ref('')
+const explainBusinessUnits = ref<ExplainBusinessUnit[]>([])
+const explainLoading = ref(false)
+const explainError = ref('')
+
+const explainBusinessUnitItems = computed<ExplainBusinessUnitSelectItem[]>(() => (
+  explainBusinessUnits.value.map((unit) => ({
+    id: unit.id,
+    name: unit.name,
+    hallId: unit.hallId,
+    previewImageUrl: unit.previewImageUrl,
+    guideStopCount: unit.guideStopCount
+  }))
+))
+
+const syncPageTitle = (title: string) => {
+  uni.setNavigationBarTitle({ title })
+  if (typeof document !== 'undefined') document.title = title
+}
+
+onLoad(async (options: any = {}) => {
+  const hallId = Array.isArray(options.hallId) ? options.hallId[0] : options.hallId
+  const hallName = Array.isArray(options.hallName) ? options.hallName[0] : options.hallName
+
+  selectedExplainHallId.value = hallId || ''
+  selectedExplainHallName.value = hallName || '业务单元'
+  syncPageTitle(selectedExplainHallName.value)
+
+  if (!selectedExplainHallId.value) {
+    explainError.value = '缺少展厅参数，请返回讲解列表后重试'
+    return
+  }
+
+  explainLoading.value = true
+  try {
+    explainBusinessUnits.value = await explainUseCase.loadTemporaryBusinessUnitsByHall(selectedExplainHallId.value)
+  } catch (error) {
+    explainError.value = '展厅讲解点加载失败，请稍后重试'
+  } finally {
+    explainLoading.value = false
+  }
+})
+
+const handleExplainBusinessUnitClick = (unitId: string) => {
+  const unit = explainBusinessUnits.value.find((item) => item.id === unitId)
+  const params = new URLSearchParams({
+    hallId: selectedExplainHallId.value,
+    hallName: selectedExplainHallName.value,
+    unitId,
+    unitName: unit?.name || '讲解点'
+  })
+
+  uni.navigateTo({
+    url: `/pages/explain/guide-stop-list?${params.toString()}`
+  })
+}
+
+const goBackToExplainHallList = () => {
+  uni.redirectTo({
+    url: '/pages/explain/list',
+    fail: () => {
+      uni.reLaunch({ url: '/pages/explain/list' })
+    }
+  })
+}
+
+const handleBack = () => {
+  const pages = getCurrentPages()
+  const previousPage = pages.length >= 2 ? pages[pages.length - 2] : null
+
+  if (previousPage?.route === 'pages/explain/list') {
+    uni.navigateBack({
+      delta: 1,
+      fail: goBackToExplainHallList
+    })
+    return
+  }
+
+  goBackToExplainHallList()
+}
+
+const handleTopTabChange = (tab: GuideTopTab) => {
+  navigateToGuideTopTab(tab)
+}
+</script>
+
+<style scoped lang="scss">
+.explain-business-unit-page {
+  position: absolute;
+  inset: 0;
+  background: #edf0ea;
+}
+</style>

src/pages/explain/guide-stop-list.vue

@@ -3,7 +3,6 @@
     active-tab="explain"
     variant="static"
     :show-top-tabs="false"
-    show-back
     @tab-change="handleTopTabChange"
     @back="handleBack"
   >

src/pages/explain/list.vue

@@ -3,8 +3,6 @@
     active-tab="explain"
     variant="static"
     :show-top-tabs="false"
-    show-back
-    back-label="讲解首页"
     @tab-change="handleTopTabChange"
     @back="handleBack"
   >