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

spec/controllers/public/api/v1/portals/articles_controller_spec.rb

@@ -58,6 +58,23 @@ RSpec.describe 'Public Articles API', type: :request do
       expect(response_data[1][:views]).to eq(1)
       expect(response_data.last[:id]).to eq(article.id)
     end
+
+    it 'limits results based on per_page parameter' do
+      get "/hc/#{portal.slug}/#{category.locale}/articles.json", params: { per_page: 2 }
+
+      expect(response).to have_http_status(:success)
+      response_data = JSON.parse(response.body, symbolize_names: true)[:payload]
+      expect(response_data.length).to eq(2)
+      expect(JSON.parse(response.body, symbolize_names: true)[:meta][:articles_count]).to eq(5)
+    end
+
+    it 'uses default items per page if per_page is less than 1' do
+      get "/hc/#{portal.slug}/#{category.locale}/articles.json", params: { per_page: 0 }
+
+      expect(response).to have_http_status(:success)
+      response_data = JSON.parse(response.body, symbolize_names: true)[:payload]
+      expect(response_data.length).to eq(3)
+    end
   end
 
   describe 'GET /public/api/v1/portals/:slug/articles/:id' do