Auto-allocate to a line

As of now it is necessary to allocate funds manually. For common categories with an expected spend, this is fine, because you can just set a baseline allocation and adjust it monthly as needed. However, if you have a category where you sometimes spend but not all the time, it would be nice to be able to auto-allocate funds equal to the expenses of the line.

Eg, travel. I don’t buy flights much so I don’t have any preset or carryover allocation, but when I do fly, I have to go to the travel line and allocate exactly the cost of the flight to take it out of my allocation instead of my available (which would be negative). Instead, there could be a toggle to auto-allocate that automatically does this for my travel line.