[OPEN LOW] Building mode undo doesn't reset building budget

This is a fairly basic issue, but I can't seem to find any topic mentioning it. When any items are built or constructed in building mode, the budget shows the cost in the building category, but the cost is not reset if the undo button is used. This is a problem when one of the goals is to have a profit: if you undo constructing an expensive room a few times to see how best to fit it, it quickly becomes impossible to turn a profit that day as the cost of each attempt piles up.

Reproduction steps:
- Note the building part of the budget.
- In building mode, perform any action with a positive cost (that's not irreversible), then undo it.
- Notice how the building part of the budget reflects the above positive cost but not the fact that it was supposed to be undone, while the balance does reflect the change (or rather, remains unchanged overall).

I figure this should be fairly easy to fix, but another related issue might not be: if you use the floor constructor to extend floor space, undoing those actions leaves a solid black plane. Feel free to make a separate bug report of that.

Hi, thanks for joining the forums to report the issue(s)! Let me check if I can reproduce these, hopefully both will be an easy fix as you mentioned. Btw yes, it's quite strange that nobody (including us) noticed the problems as undo has been in the game for around a year already.