feat: Articles store integration (#5133)

app/views/api/v1/accounts/articles/_article.json.jbuilder

@@ -5,6 +5,7 @@ json.content article.content
 json.description article.description
 json.status article.status
 json.account_id article.account_id
+json.updated_at article.updated_at.to_i
 
 if article.portal.present?
   json.portal do

app/views/api/v1/accounts/articles/index.json.jbuilder

@@ -4,5 +4,5 @@ end
 
 json.meta do
   json.current_page @current_page
-  json.articles_count @articles.size
+  json.articles_count @articles_count
 end