Fix fontend tests, move next button in list view

vue/src/components/__tests__/AppNav.spec.js

@@ -7,6 +7,15 @@ import { useFeeds } from '../../composables/useFeeds'
 
 vi.mock('axios')
 
+// jsdom does not implement IntersectionObserver, but AppNav sets one up on mount
+// to track whether the list view's title is scrolled into view.
+class FakeIntersectionObserver {
+  observe() {}
+  unobserve() {}
+  disconnect() {}
+}
+vi.stubGlobal('IntersectionObserver', FakeIntersectionObserver)
+
 describe('AppNav', () => {
   let router
 

vue/src/components/__tests__/RssFeeds.spec.js

@@ -252,13 +252,13 @@ describe('RssFeeds', () => {
     useFeeds().toggleViewMode()
     await flushPromises()
 
-    expect(wrapper.find('.article-single .feed-title').text()).toBe('Article one')
+    expect(wrapper.find('.article-single .article-feature__title').text()).toBe('Article one')
     // Same as in list view: the readable content is loaded on demand by
     // clicking the headline, not fetched automatically on entering the view.
     expect(axios.post).not.toHaveBeenCalled()
     expect(wrapper.find('.article-single .feed-original-link a').exists()).toBe(true)
 
-    await wrapper.find('.article-single .feed-title').trigger('click')
+    await wrapper.find('.article-single .article-feature__title').trigger('click')
     await flushPromises()
 
     expect(axios.post).toHaveBeenCalledWith('/api/v1/article/read', { url: 'https://example.test/1' }, expect.anything())
@@ -269,13 +269,13 @@ describe('RssFeeds', () => {
     await wrapper.findAll('.article-nav__btn')[1].trigger('click')
     await flushPromises()
 
-    expect(wrapper.find('.article-single .feed-title').text()).toBe('Article two')
+    expect(wrapper.find('.article-single .article-feature__title').text()).toBe('Article two')
     expect(wrapper.findAll('.article-nav__btn')[1].attributes('disabled')).toBeDefined()
 
     await wrapper.findAll('.article-nav__btn')[0].trigger('click')
     await flushPromises()
 
-    expect(wrapper.find('.article-single .feed-title').text()).toBe('Article one')
+    expect(wrapper.find('.article-single .article-feature__title').text()).toBe('Article one')
   })
 
   it('drops articles read while paging through article view once back in the list', async () => {