Adding withdrawal to contribution limits

[vaishsriram]

This PR calculates limits not only from deposits but from withdrawals also.

The solution is tested locally.

Closes #338

[afadil]

@vaishsriram, thanks for the contribution! I'm not sure about this, though.
Actually, contribution limits are used to track and enforce legal caps on how much users can deposit into regulated (tax-advantaged) accounts annually (e.g., RRSP, TFSA, FHSA in Canada or 401(k), IRA, HSA in the U.S.). These limits are defined by tax law and vary by account type.

• Only deposits count against the limit
• Withdrawals do not affect current-year room
• For some accounts, TFSA withdrawals restore room in the following year, not the current year.

[vaishsriram]

@vaishsriram, thanks for the contribution! I'm not sure about this, though. Actually, contribution limits are used to track and enforce legal caps on how much users can deposit into regulated (tax-advantaged) accounts annually (e.g., RRSP, TFSA, FHSA in Canada or 401(k), IRA, HSA in the U.S.). These limits are defined by tax law and vary by account type.

• Only deposits count against the limit
• Withdrawals do not affect current-year room
• For some accounts, TFSA withdrawals restore room in the following year, not the current year.

@afadil thanks for the detailed response, and apologies for the delay in getting back.

I see what you mean for regulated, tax-advantaged accounts (RRSP, TFSA, 401k, etc.) where withdrawals don’t affect contribution room. That makes sense.

That said, I was thinking more about a different use case: after-tax contribution accounts where a user might still want to set an annual limit for themselves, and both deposits and withdrawals would affect that limit.

From your suggestion, it sounds like modeling this as a goal with time constraints (e.g., yearly savings goals) could be a better fit. The one wrinkle I see is that the same account can’t be assigned to multiple goals today, so I’m curious if you think extending the goal system (or making contribution limits a first-class property of an account) would be a more flexible path forward.

Do you think goals with dates offer a more flexible alternative, or is the current setup still the better option?