feat: Add an option on the dashboard to allow switching help center layout (#14491)

<img width="633" height="431" alt="Screenshot 2026-05-18 at 12 32 55 PM"
src="https://github.com/user-attachments/assets/682d4c5f-4c76-465b-8d2f-92fbc2bb2a40"
/>

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Co-authored-by: Muhsin Keloth <muhsinkeramam@gmail.com>
Co-authored-by: Sivin Varghese <64252451+iamsivin@users.noreply.github.com>
Co-authored-by: iamsivin <iamsivin@gmail.com>

spec/controllers/api/v1/accounts/portals_controller_spec.rb

@@ -170,7 +170,10 @@ RSpec.describe 'Api::V1::Accounts::Portals', type: :request do
             'allowed_locales' => [
               { 'articles_count' => 0, 'categories_count' => 0, 'code' => 'en', 'draft' => false },
               { 'articles_count' => 0, 'categories_count' => 0, 'code' => 'es', 'draft' => true }
-            ]
+            ],
+            'default_locale' => 'en',
+            'layout' => 'classic',
+            'social_profiles' => {}
           }
         )
       end