fix scroll to mark read bug

vue/src/composables/useFeeds.js

@@ -199,13 +199,18 @@ function markCurrentArticleRead() {
   }
 }
 
-function leaveArticleView() {
+async function leaveArticleView() {
   // Articles paged past in article view were marked read but deliberately kept
   // in place so currentIndex stayed valid — drop them now so they don't keep
   // showing up in the list view.
   feeds.value = feeds.value.filter(feed => !feed.read)
   currentIndex.value = 0
   viewMode.value = 'list'
+  // The v-if on the list container tears down and recreates all .observe DOM
+  // nodes when switching views, so the intersection observer must be
+  // re-pointed at the new elements after Vue has finished rendering.
+  await nextTick()
+  setupIntersectionObserver()
 }
 
 function toggleViewMode() {