feat: Voice channel creation Flow (#11775)

This PR introduces a new channel type for voice conversations.

ref: #11481 

## Changes

- Add database migration for channel_voice table with phone_number and
provider_config
- Create Channel::Voice model with E.164 phone number validation and
Twilio config validation
- Add voice channel association to Account model
- Extend inbox helpers and types to support voice channels
- Add voice channel setup UI with Twilio configuration form
- Include voice channel in channel factory and list components
- Add API routes and store actions for voice channel creation
- Add comprehensive translations for voice channel management

---------

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

app/controllers/api/v1/accounts/inboxes_controller.rb

@@ -81,11 +81,15 @@ class Api::V1::Accounts::InboxesController < Api::V1::Accounts::BaseController
   end
 
   def create_channel
-    return unless %w[web_widget api email line telegram whatsapp sms].include?(permitted_params[:channel][:type])
+    return unless allowed_channel_types.include?(permitted_params[:channel][:type])
 
     account_channels_method.create!(permitted_params(channel_type_from_params::EDITABLE_ATTRS)[:channel].except(:type))
   end
 
+  def allowed_channel_types
+    %w[web_widget api email line telegram whatsapp sms]
+  end
+
   def update_inbox_working_hours
     @inbox.update_working_hours(params.permit(working_hours: Inbox::OFFISABLE_ATTRS)[:working_hours]) if params[:working_hours]
   end