refactor(voice): expose voice_enabled? on Channel::Whatsapp for duck-typed checks

app/models/channel/whatsapp.rb

@@ -40,6 +40,13 @@ class Channel::Whatsapp < ApplicationRecord
     'Whatsapp'
   end
 
+  # Mirrors Channel::TwilioSms#voice_enabled? so the call subsystem can
+  # duck-type across providers. Backed by the JSON config rather than a column
+  # because all other WhatsApp Cloud capability flags live in `provider_config`.
+  def voice_enabled?
+    provider_config['calling_enabled'].present?
+  end
+
   def provider_service
     if provider == 'whatsapp_cloud'
       Whatsapp::Providers::WhatsappCloudService.new(whatsapp_channel: self)

enterprise/app/builders/enterprise/messages/message_builder.rb

@@ -7,17 +7,10 @@ module Enterprise::Messages::MessageBuilder
     super
   end
 
+  # Voice-capable channels (Twilio voice, WhatsApp Cloud Calling) all expose
+  # `voice_enabled?`; treat any of them as eligible for the incoming voice_call
+  # bubble bypass.
   def voice_call_inbox?
-    twilio_voice_inbox? || whatsapp_call_inbox?
-  end
-
-  def twilio_voice_inbox?
-    inbox = @conversation.inbox
-    inbox.channel_type == 'Channel::TwilioSms' && inbox.channel.voice_enabled?
-  end
-
-  def whatsapp_call_inbox?
-    inbox = @conversation.inbox
-    inbox.channel_type == 'Channel::Whatsapp' && inbox.channel.provider_config['calling_enabled']
+    @conversation.inbox.channel.try(:voice_enabled?)
   end
 end

enterprise/app/services/whatsapp/call_permission_reply_service.rb

@@ -2,7 +2,7 @@ class Whatsapp::CallPermissionReplyService
   pattr_initialize [:inbox!, :params!]
 
   def perform
-    return unless inbox.channel.provider_config['calling_enabled']
+    return unless inbox.channel.voice_enabled?
 
     reply_data = extract_reply_data
     return unless reply_data&.dig(:accepted)

enterprise/app/services/whatsapp/incoming_call_service.rb

@@ -2,7 +2,7 @@ class Whatsapp::IncomingCallService
   pattr_initialize [:inbox!, :params!]
 
   def perform
-    return unless inbox.channel.provider_config['calling_enabled']
+    return unless inbox.channel.voice_enabled?
 
     Array(params[:calls]).each { |c| handle_event(c.with_indifferent_access) }
   end