Allow support for one-off budget increases for planned expenses like down payments, vacations, or other large expenses. Maybe this could be tracked on an annual or more holistic basis.

This relates to Savings and goals (https://feedback.lunchmoney.app/general-feature-request/p/savings-and-goals) but can also help when you already have the money saved for the purchase (it's no longer a goal to track, but a planned expense by that point.