feat(whatsapp): enable reconfigure for embedded signup inboxes (#15038)

app/controllers/api/v1/accounts/whatsapp/authorizations_controller.rb

@@ -1,4 +1,6 @@
 class Api::V1::Accounts::Whatsapp::AuthorizationsController < Api::V1::Accounts::BaseController
+  # Reconfiguring/reauthorizing a live inbox swaps its credentials, so restrict it to admins.
+  before_action :check_admin_authorization?, if: -> { params[:inbox_id].present? }
   before_action :fetch_and_validate_inbox, if: -> { params[:inbox_id].present? }
 
   # POST /api/v1/accounts/:account_id/whatsapp/authorization
@@ -31,7 +33,7 @@ class Api::V1::Accounts::Whatsapp::AuthorizationsController < Api::V1::Accounts:
   end
 
   def validate_reauthorization_required
-    return if @inbox.channel.reauthorization_required? || can_upgrade_to_embedded_signup?
+    return if @inbox.channel.reauthorization_required? || can_reconfigure_channel?
 
     render json: {
       success: false,
@@ -39,10 +41,13 @@ class Api::V1::Accounts::Whatsapp::AuthorizationsController < Api::V1::Accounts:
     }, status: :unprocessable_entity
   end
 
-  def can_upgrade_to_embedded_signup?
+  def can_reconfigure_channel?
     channel = @inbox.channel
     return false unless channel.provider == 'whatsapp_cloud'
 
+    # Reconfiguring a live embedded-signup channel requires the feature flag.
+    return Current.account.feature_enabled?('whatsapp_reconfigure') if channel.provider_config['source'] == 'embedded_signup'
+
     true
   end