chore(voice): trim redundant comments on backend voice files

Pass through pla-150 to drop comments that just describe what the next
line already does:
- whatsapp_calls_controller: removed the Twilio-comparison note (the
  ensure_calling_enabled body says it), the SDP-forwarding tagline, and
  tightened the 138006/transport-error/wamid blocks.
- call.rb: dropped trivial annotations on STATUSES / TERMINAL_STATUSES;
  the names already say what they are.
- send_on_channel_service: collapsed the two-line voice_call rationale
  into one — the surrounding context covers the rest.

No behavior change. 33/33 enterprise call specs still pass; rubocop clean.

app/services/base/send_on_channel_service.rb

@@ -46,8 +46,7 @@ class Base::SendOnChannelService
   def invalid_message?
     # private notes aren't send to the channels
     # we should also avoid the case of message loops, when outgoing messages are created from channel
-    # voice_call bubbles are call status indicators, not deliverable messages — skip the send pipeline
-    # otherwise it falls through to "Template not found" / 24-hour-window errors
+    # voice_call bubbles are call status indicators, not deliverable messages
     message.private? || outgoing_message_originated_from_channel? || message.content_type == 'voice_call'
   end
 

enterprise/app/controllers/api/v1/accounts/whatsapp_calls_controller.rb

@@ -59,7 +59,6 @@ class Api::V1::Accounts::WhatsappCallsController < Api::V1::Accounts::BaseContro
     authorize @conversation, :show?
   end
 
-  # Twilio voice also exposes voice_enabled? but uses a different initiation path.
   def ensure_calling_enabled
     channel = @conversation.inbox.channel
     return if channel.is_a?(Channel::Whatsapp) && channel.voice_enabled?
@@ -98,7 +97,6 @@ class Api::V1::Accounts::WhatsappCallsController < Api::V1::Accounts::BaseContro
     'uploaded'
   end
 
-  # Browser-built SDP offer is forwarded to Meta; the connect webhook later delivers Meta's answer.
   def create_outbound_call
     contact_phone = @conversation.contact.phone_number.delete('+')
     result = provider_service.initiate_call(contact_phone, params[:sdp_offer])
@@ -112,9 +110,8 @@ class Api::V1::Accounts::WhatsappCallsController < Api::V1::Accounts::BaseContro
     )
   end
 
-  # 138006 = no call permission yet; send opt-in template (throttled) and surface state to FE.
-  # Lock the conversation so concurrent initiate requests can't both pass the throttle gate
-  # and double-send the opt-in template.
+  # Meta error 138006 means the contact hasn't opted in yet; send the opt-in
+  # template (throttled, behind a conversation lock to prevent double-send).
   def render_permission_request
     status = nil
     @conversation.with_lock do
@@ -142,8 +139,7 @@ class Api::V1::Accounts::WhatsappCallsController < Api::V1::Accounts::BaseContro
     last_requested.present? && Time.zone.parse(last_requested) > PERMISSION_REQUEST_THROTTLE.ago
   end
 
-  # Treat transport errors the same as a falsy provider return so the action renders 422
-  # rather than letting Faraday/HTTParty exceptions bubble up as 500s.
+  # Treat transport errors as a falsy return so we render 422 rather than 500.
   def send_permission_request_safely
     provider_service.send_call_permission_request(@conversation.contact.phone_number.delete('+'))
   rescue StandardError => e
@@ -151,7 +147,7 @@ class Api::V1::Accounts::WhatsappCallsController < Api::V1::Accounts::BaseContro
     nil
   end
 
-  # Record the wamid so the reply webhook can match context.id back to this conversation.
+  # Stash the outbound wamid so the reply webhook can match context.id back here.
   def record_permission_request_wamid(sent)
     attrs = (@conversation.additional_attributes || {}).merge(
       'call_permission_requested_at' => Time.current.iso8601,

enterprise/app/models/call.rb

@@ -29,9 +29,7 @@
 #  index_calls_on_provider_and_provider_call_id   (provider,provider_call_id) UNIQUE
 #
 class Call < ApplicationRecord
-  # All valid call statuses
   STATUSES = %w[ringing in_progress completed no_answer failed].freeze
-  # Statuses where the call is finished and won't change again
   TERMINAL_STATUSES = %w[completed no_answer failed].freeze
 
   store_accessor :meta, :conference_sid, :recording_sid, :parent_call_sid, :initiated_at, :ended_at