- whatsapp_sync: send patients concurrently (asyncio.gather + semaphore=10) instead of sequentially — eliminates long waits with many patients - envios_erp: auto-refresh historial every 60s when scheduler tab is active - main: wrap scheduler job to catch exceptions and log them to sync_wa_log so failures are visible in historial Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>