chore: 清理备份文件目录中的原始页面文件

移除 docs/backups/original-pages/ 目录下的四个备份文件：
- message-index.vue.bak
- product-center-index.vue.bak
- search-index.vue.bak
- material-list-index.vue.bak

这些文件是开发过程中的临时备份，现已不再需要。

-<template>
-  <view class="min-h-screen bg-[#F9FAFB] pb-safe">
-    <NavHeader title="我的消息" />
-
-    <!-- 列表区域 -->
-    <view class="p-4">
-      <template v-if="messageList.length > 0">
-        <view
-          v-for="item in messageList"
-          :key="item.id"
-          class="bg-white rounded-xl p-4 mb-3 shadow-sm active:opacity-70 transition-opacity"
-          @tap="handleItemClick(item)"
-        >
-          <view class="flex justify-between items-start mb-2">
-            <view class="flex-1 mr-2">
-              <view class="text-base font-bold text-gray-900 line-clamp-1">
-                {{ item.title }}
-              </view>
-            </view>
-            <text class="text-xs text-gray-400 shrink-0 mt-1">
-              {{ item.create_time }}
-            </text>
-          </view>
-
-          <view class="text-sm text-gray-600 line-clamp-2 leading-relaxed">
-            {{ item.intro || item.content || '暂无简介' }}
-          </view>
-        </view>
-
-        <!-- 加载更多/没有更多 -->
-        <view class="py-4 text-center text-[24rpx] text-gray-400">
-          <text v-if="loading">加载中...</text>
-          <text v-else-if="!hasMore">没有更多了</text>
-          <text v-else>上拉加载更多</text>
-        </view>
-      </template>
-
-      <!-- 空状态 -->
-      <nut-empty
-        v-else-if="!loading && messageList.length === 0"
-        description="暂无消息"
-        image="empty"
-      />
-    </view>
-  </view>
-</template>
-
-<script setup>
-import { ref } from 'vue'
-import { useLoad, usePullDownRefresh, useReachBottom, stopPullDownRefresh } from '@tarojs/taro'
-import { useGo } from '@/hooks/useGo'
-import NavHeader from '@/components/NavHeader.vue'
-import { myListAPI } from '@/api/news'
-import { mockMessageListAPI } from '@/utils/mockData'
-
-// ⚠️ MOCK 数据开关 - 开发环境使用 mock 数据，生产环境使用真实 API
-const USE_MOCK_DATA = process.env.NODE_ENV === 'development'
-
-const go = useGo()
-
-const messageList = ref([])
-const page = ref(1)
-const limit = ref(10)
-const hasMore = ref(true)
-const loading = ref(false)
-
-/**
- * @description 加载消息列表
- * @param {boolean} refresh 是否刷新
- */
-const fetchMessageList = async (refresh = false) => {
-  if (loading.value) return
-
-  if (refresh) {
-    page.value = 1
-    hasMore.value = true
-  } else if (!hasMore.value) {
-    return
-  }
-
-  loading.value = true
-
-  try {
-    console.log('[Message] 使用 Mock 数据:', USE_MOCK_DATA)
-
-    // 根据开关选择使用真实 API 或 Mock 数据
-    const res = USE_MOCK_DATA
-      ? await mockMessageListAPI({
-          page: page.value,
-          limit: limit.value
-        })
-      : await myListAPI({
-          page: page.value,
-          limit: limit.value
-        })
-
-    if (res.code === 1) {
-      const list = res.data?.list || []
-
-      if (refresh) {
-        messageList.value = list
-      } else {
-        messageList.value = [...messageList.value, ...list]
-      }
-
-      if (list.length < limit.value) {
-        hasMore.value = false
-      } else {
-        page.value++
-      }
-    }
-  } catch (err) {
-    console.error('获取消息列表失败:', err)
-  } finally {
-    loading.value = false
-    if (refresh) {
-      stopPullDownRefresh()
-    }
-  }
-}
-
-/**
- * @description 跳转到详情页
- * @param {Object} item 消息对象
- */
-const handleItemClick = (item) => {
-  go('/pages/message-detail/index', { id: item.id })
-}
-
-// 页面加载
-useLoad(() => {
-  fetchMessageList(true)
-})
-
-// 下拉刷新
-usePullDownRefresh(() => {
-  fetchMessageList(true)
-})
-
-// 上拉加载更多
-useReachBottom(() => {
-  fetchMessageList()
-})
-</script>
-
-<style lang="less">
-/* Scoped styles if needed */
-</style>