Fix voicemail and queue announcement issues

- Fixed phone agents getting 'Unauthorized' error when accessing voicemails by checking for twp_access_voicemails capability
- Fixed missing ElevenLabs parameter in queue TwiML generation that prevented announcement messages
- Fixed IVR voicemail messages not being saved correctly - now properly assigns message field based on action type
- Added proper permission checks for both ajax_get_voicemail and ajax_get_voicemail_audio functions

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

includes/class-twp-workflow.php

@@ -975,7 +975,8 @@ class TWP_Workflow {
                 return self::create_voicemail_twiml($action, $elevenlabs);
                 
             case 'queue':
-                return self::create_queue_twiml($action);
+                $elevenlabs = new TWP_ElevenLabs_API();
+                return self::create_queue_twiml($action, $elevenlabs);
                 
             case 'ring_group':
                 return self::create_ring_group_twiml($action);