chore: Limit the number of articles retrieved by widget (#11095)

The UI displays only six articles, and this update introduces a per_page
parameter to control the number of articles returned per API call. The
value is capped between 1 and 100, with a default fallback if a lower
number is set.

This change is necessary due to high website traffic, where excessive
payloads are returned without adding value.

**Changes:** 
- Add index to status, account_id, portal_id, views.
- Add per_page param in the API.
- Update the code in the frontend to fetch only 6

app/controllers/public/api/v1/portals/articles_controller.rb

@@ -6,17 +6,25 @@ class Public::Api::V1::Portals::ArticlesController < Public::Api::V1::Portals::B
   layout 'portal'
 
   def index
-    @articles = @portal.articles.published
+    @articles = @portal.articles.published.includes(:category, :author)
     @articles_count = @articles.count
     search_articles
     order_by_sort_param
-    @articles = @articles.page(list_params[:page]) if list_params[:page].present?
+    limit_results
   end
 
   def show; end
 
   private
 
+  def limit_results
+    return if list_params[:per_page].blank?
+
+    per_page = [list_params[:per_page].to_i, 100].min
+    per_page = 25 if per_page < 1
+    @articles = @articles.page(list_params[:page]).per(per_page)
+  end
+
   def search_articles
     @articles = @articles.search(list_params) if list_params.present?
   end
@@ -45,7 +53,7 @@ class Public::Api::V1::Portals::ArticlesController < Public::Api::V1::Portals::B
   end
 
   def list_params
-    params.permit(:query, :locale, :sort, :status, :page)
+    params.permit(:query, :locale, :sort, :status, :page, :per_page)
   end
 
   def permitted_params