feat(envios/erp): add manual sync trigger endpoint and test UI

- POST /envios/erp/sync-now?ventana_min=N calls sync_recientes with configurable window
- sync_recientes() now returns a result dict (ok, total, created, updated, skipped, errores, detalle)
- ERP tab shows a "Prueba manual" card with ventana selector (2m / 30m / 2h / hoy) and result breakdown

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

app/routes/envios.py

@@ -1,6 +1,8 @@
-from fastapi import APIRouter, Request, Depends
+from fastapi import APIRouter, Request, Depends, Query
+from fastapi.responses import JSONResponse
 from app.auth import get_current_user
 from app.database import get_connection
+from app.services.scheduler import sync_recientes
 
 router = APIRouter(prefix="/envios", tags=["envios"])
 
@@ -24,3 +26,12 @@ async def envios_erp(request: Request, user: dict = Depends(get_current_user)):
         "wa_configurado": bool(wa_url and wa_key),
         "wa_url": wa_url,
     })
+
+
+@router.post("/erp/sync-now")
+async def erp_sync_now(
+    ventana_min: int = Query(default=30, ge=1, le=1440),
+    user: dict = Depends(get_current_user),
+):
+    resultado = await sync_recientes(ventana_min=ventana_min)
+    return JSONResponse(resultado)