fix(turnero): route incoming messages by phone_number_id and fix WhatsAppService canal

- WhatsAppService($canal): when 'turnero', swaps phoneNumberId to whatsapp_phone_number_id_turnero
  so outgoing messages actually go from the turnero number (not the main bot)
- webhook.php: reads metadata.phone_number_id from the payload and compares it to
  whatsapp_phone_number_id_turnero; if it matches, saves canal='turnero' and skips bot processing
- Previously all incoming messages had canal=NULL/bot so Chat Turnero never saw them,
  and all outgoing messages from Chat Turnero were sent via the wrong (main bot) number

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

services/WhatsAppService.php

@@ -22,14 +22,23 @@ class WhatsAppService
     private $db;
     private $rateLimitMonitor;
 
-    public function __construct()
+    public function __construct($canal = null)
     {
         // Obtener configuración desde base de datos
         $config = getWhatsAppConfigFromDB();
-        
-        $this->token = $config['token']; // Usar token de BD
-        $this->phoneNumberId = $config['phone_number_id']; // Usar phone_number_id de BD
-        $this->apiUrl = $config['api_url'] ?: 'https://graph.facebook.com/v22.0/'; // Usar api_url de BD
+
+        $this->token = $config['token'];
+        $this->phoneNumberId = $config['phone_number_id'];
+        $this->apiUrl = $config['api_url'] ?: 'https://graph.facebook.com/v22.0/';
+
+        // Si se especifica canal 'turnero', usar el phone ID del número turnero
+        if ($canal === 'turnero') {
+            $turneroPhoneId = getConfigFromDB('whatsapp_phone_number_id_turnero', '');
+            if ($turneroPhoneId) {
+                $this->phoneNumberId = $turneroPhoneId;
+            }
+        }
+
         $this->db = Database::getInstance();
         
         // Inicializar monitor de rate limit