feat: disable helpcenter on hacker plans (#12068)

This change blocks Help Center access for default/Hacker-plan accounts
and closes the downgrade gap that could leave `help_center` enabled
after a subscription falls back to the default cloud plan.

Fixes: none
Closes: none

## Why

Default-plan accounts should not be able to access the Help Center, but
the downgrade fallback path only reset the plan name and did not
reconcile premium feature flags. That meant some accounts could keep
`help_center` enabled even after landing back on the Hacker/default
plan.

## What this change does

- blocks Help Center portal and article access for default/Hacker-plan
accounts
- reconciles premium feature flags when a subscription falls back to the
default cloud plan, so `help_center` is disabled immediately instead of
waiting for a later webhook
- preserves existing account `custom_attributes` during Stripe customer
recreation instead of overwriting them
- adds Enterprise coverage for the default-plan access checks on hosted
and custom-domain Help Center routes
- fixes the public access check to use the resolved portal object so
blocked requests return the intended response instead of raising an
error

## Validation

1. Create or use an account on the default/Hacker cloud plan with an
active portal.
2. Visit the portal home page and a published article on both the
Chatwoot-hosted URL and a configured custom domain.
3. Confirm the Help Center is blocked for that account.
4. Downgrade a paid account back to the default/Hacker plan through the
Stripe webhook flow.
5. Confirm `help_center` is disabled right after the downgrade fallback
is processed and the account can no longer access the Help Center.

---------

Co-authored-by: Muhsin Keloth <muhsinkeramam@gmail.com>
Co-authored-by: Sojan Jose <sojan@pepalo.com>

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

@@ -1,6 +1,7 @@
 class Public::Api::V1::Portals::ArticlesController < Public::Api::V1::Portals::BaseController
   before_action :ensure_custom_domain_request, only: [:show, :index]
   before_action :portal
+  before_action :ensure_portal_feature_enabled
   before_action :set_category, except: [:index, :show, :tracking_pixel]
   before_action :set_article, only: [:show]
   layout 'portal'

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

@@ -1,6 +1,7 @@
 class Public::Api::V1::Portals::CategoriesController < Public::Api::V1::Portals::BaseController
   before_action :ensure_custom_domain_request, only: [:show, :index]
   before_action :portal
+  before_action :ensure_portal_feature_enabled
   before_action :set_category, only: [:show]
   layout 'portal'
 

app/controllers/public/api/v1/portals_controller.rb

@@ -1,7 +1,8 @@
 class Public::Api::V1::PortalsController < Public::Api::V1::Portals::BaseController
   before_action :ensure_custom_domain_request, only: [:show]
-  before_action :portal
   before_action :redirect_to_portal_with_locale, only: [:show]
+  before_action :portal
+  before_action :ensure_portal_feature_enabled
   layout 'portal'
 
   def show
@@ -24,6 +25,7 @@ class Public::Api::V1::PortalsController < Public::Api::V1::Portals::BaseControl
   def redirect_to_portal_with_locale
     return if params[:locale].present?
 
+    portal
     redirect_to "/hc/#{@portal.slug}/#{@portal.default_locale}"
   end
 end

app/controllers/public_controller.rb

@@ -18,4 +18,11 @@ class PublicController < ActionController::Base
       Please send us an email at support@chatwoot.com with the custom domain name and account API key"
     }, status: :unauthorized and return
   end
+
+  def ensure_portal_feature_enabled
+    return unless ChatwootApp.chatwoot_cloud?
+    return if @portal.account.feature_enabled?('help_center')
+
+    render 'public/api/v1/portals/not_active', status: :payment_required
+  end
 end

app/views/public/api/v1/portals/not_active.html.erb

@@ -0,0 +1,12 @@
+<div class="max-w-6xl h-full w-full flex-grow flex flex-col items-center justify-center mx-auto py-16 px-4 relative">
+    <div class="text-center mb-12">
+        <div class="mx-auto flex h-20 w-20 items-center justify-center rounded-full bg-slate-100 text-slate-500 dark:bg-slate-800 dark:text-slate-300">
+            <span class="text-5xl font-medium">i</span>
+        </div>
+    </div>
+    <h1 class="text-6xl text-center font-semibold text-slate-800 dark:text-slate-100 leading-relaxed"><%= I18n.t('public_portal.not_active.title') %></h1>
+    <p class="text-center text-slate-700 dark:text-slate-300 my-1"><%= I18n.t('public_portal.not_active.description') %></p>
+    <div class="text-center my-8">
+        <p class="text-slate-600 dark:text-slate-400 text-sm"><%= I18n.t('public_portal.not_active.action') %></p>
+    </div>
+</div>