Freshness monitors now handle day/night seasonality

Last year, we improved freshness monitors to handle weekly patterns much better. This is useful if your tables update frequently during the week, but not on the weekends.

Now, we support the same for daily patterns. If your tables update frequently during the day and infrequently at night, the threshold will adjust to be much tighter during the day and much wider at night.

This is particularly common in financial services, where many data pipelines update frequently during market hours but not at night or during the weekend.