fix: reducir ventana de exámenes recientes a 5 minutos

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

api/lab/get_examenes_rips.php

@@ -19,7 +19,7 @@ $cacheRow = db()->prepare(
      FROM rips_examenes_pendientes
      WHERE numero_documento = ?
        AND DATE(created_at) = CURDATE()
-       AND created_at >= NOW() - INTERVAL 30 MINUTE
+       AND created_at >= NOW() - INTERVAL 5 MINUTE
      ORDER BY created_at DESC
      LIMIT 1"
 );