Correcciones en controladores de postulaciones y contratos

- Corregir método distance() a withinDistanceTo() para consultas espaciales
- Corregir parsing de fecha/hora con timezone America/Tijuana
- Comentar código de WhatsApp no configurado

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

app/Http/Controllers/SupplierController.php

@@ -1220,7 +1220,7 @@ class SupplierController extends Controller
       }
 
       $distance = 0.5;
-      $postulations = Postulations::distance('location', $supplier->location, $distance)->orderBy('created_at', 'DESC')->get();
+      $postulations = Postulations::withinDistanceTo('location', $supplier->location, $distance)->orderBy('created_at', 'DESC')->get();
 
       $postulationsinfo = array();