feat: remember home tab selection

This reverts commit 2c5462cd97.

frontend_nuxt/pages/index.vue

@@ -147,16 +147,17 @@ const categoryOptions = ref([])
 const isLoadingMore = ref(false)
 
 const topics = ref(['最新回复', '最新', '排行榜' /*, '热门', '类别'*/])
+const selectedTopicCookie = useCookie('homeTab')
 const selectedTopic = ref(
-  route.query.view === 'ranking' ? '排行榜' : route.query.view === 'latest' ? '最新' : '最新回复',
+  selectedTopicCookie.value
+    ? selectedTopicCookie.value
+    : route.query.view === 'ranking'
+      ? '排行榜'
+      : route.query.view === 'latest'
+        ? '最新'
+        : '最新回复',
 )
-
-if (import.meta.client) {
-  const storedTopic = localStorage.getItem('home-selected-topic')
-  if (storedTopic && topics.value.includes(storedTopic)) {
-    selectedTopic.value = storedTopic
-  }
-}
+if (!selectedTopicCookie.value) selectedTopicCookie.value = selectedTopic.value
 const articles = ref([])
 const page = ref(0)
 const pageSize = 10
@@ -182,6 +183,11 @@ onMounted(() => {
   const { category, tags } = route.query
   if (category) selectedCategorySet(category)
   if (tags) selectedTagsSet(tags)
+
+  const saved = localStorage.getItem('homeTab')
+  if (saved) {
+    selectedTopic.value = saved
+  }
 })
 
 /** 路由变更时同步筛选 **/
@@ -347,12 +353,13 @@ watch(
 watch([selectedCategory, selectedTags], () => {
   loadOptions()
 })
-watch(selectedTopic, (topic) => {
-  if (import.meta.client) {
-    localStorage.setItem('home-selected-topic', topic)
-  }
+watch(selectedTopic, (val) => {
   // 仅当需要额外选项时加载
   loadOptions()
+  selectedTopicCookie.value = val
+  if (process.client) {
+    localStorage.setItem('homeTab', val)
+  }
 })
 
 /** 选项首屏加载：服务端执行一次；客户端兜底 **/