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

db/migrate/20250315202035_add_index_to_articles.rb

@@ -0,0 +1,8 @@
+class AddIndexToArticles < ActiveRecord::Migration[7.0]
+  def change
+    add_index :articles, :status unless index_exists?(:articles, :status)
+    add_index :articles, :views unless index_exists?(:articles, :views)
+    add_index :articles, :portal_id unless index_exists?(:articles, :portal_id)
+    add_index :articles, :account_id unless index_exists?(:articles, :account_id)
+  end
+end

db/schema.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema[7.0].define(version: 2025_02_28_185548) do
+ActiveRecord::Schema[7.0].define(version: 2025_03_15_202035) do
   # These extensions should be enabled to support this database
   enable_extension "pg_stat_statements"
   enable_extension "pg_trgm"
@@ -159,9 +159,13 @@ ActiveRecord::Schema[7.0].define(version: 2025_02_28_185548) do
     t.string "slug", null: false
     t.integer "position"
     t.string "locale", default: "en", null: false
+    t.index ["account_id"], name: "index_articles_on_account_id"
     t.index ["associated_article_id"], name: "index_articles_on_associated_article_id"
     t.index ["author_id"], name: "index_articles_on_author_id"
+    t.index ["portal_id"], name: "index_articles_on_portal_id"
     t.index ["slug"], name: "index_articles_on_slug", unique: true
+    t.index ["status"], name: "index_articles_on_status"
+    t.index ["views"], name: "index_articles_on_views"
   end
 
   create_table "attachments", id: :serial, force: :cascade do |t|