AI: address review on PR #468

backend/app/controllers/posts_controller.rb

@@ -314,7 +314,9 @@ class PostsController < ApplicationController
   def viewed
     return head :unauthorized unless current_user
 
-    current_user.viewed_posts << Post.find(params[:id])
+    UserPostView.create_or_find_by!(
+        user: current_user,
+        post: Post.find(params[:id]))
     head :no_content
   end
 

backend/spec/requests/posts_spec.rb

@@ -2559,6 +2559,21 @@ RSpec.describe 'Posts API', type: :request do
 
       expect(user.reload.viewed?(post_record)).to be(true)
     end
+
+    it '204 and keeps one view on repeated requests' do
+      sign_in_as(user)
+
+      expect {
+        post "/posts/#{ post_record.id }/viewed"
+      }.to change(UserPostView, :count).by(1)
+      expect(response).to have_http_status(:no_content)
+
+      expect {
+        post "/posts/#{ post_record.id }/viewed"
+      }.not_to change(UserPostView, :count)
+      expect(response).to have_http_status(:no_content)
+      expect(user.reload.viewed?(post_record)).to be(true)
+    end
   end
 
   describe 'DELETE /posts/:id/viewed' do

frontend/src/components/TagDetailSidebar.test.tsx

@@ -39,18 +39,6 @@ describe ('TagDetailSidebar', () => {
     vi.clearAllMocks ()
   })
 
-  it ('inherits the sidebar width saved by the post list', () => {
-    localStorage.setItem ('sidebar:posts-index-tags:left:width', '320')
-
-    const { container } = renderWithProviders (
-	<TagDetailSidebar post={buildPost ()}/>)
-    const sidebar = container.querySelector<HTMLElement> (
-	'[style*="--sidebar-width"]')
-
-    expect (sidebar).toBeInTheDocument ()
-    expect (sidebar?.style.getPropertyValue ('--sidebar-width')).toBe ('320px')
-  })
-
   it ('keeps internal and external tags with the same numeric id in flat mode', () => {
     setClientTagRelationDisplayMode ('flat')
 

frontend/src/components/TagDetailSidebar.tsx

@@ -378,7 +378,7 @@ const TagDetailSidebar: FC<Props> = ({ className, post, sp }) => {
   }, [baseTags])
 
   return (
-      <SidebarComponent sidebarKey="posts-index-tags" className={className}>
+      <SidebarComponent sidebarKey="post-detail-tags" className={className}>
 	<TagSearch/>
 	<DndContext
 	    sensors={sensors}