Administrative costs for inactive users

[rinkp]

As per the TOS, once a user has had no transactions for 3 years, they can be charged an administrative fee. The first time these costs can possibly be charged is on June 30th 2025, so we SHALL send an email on June 30th 2024 to prevent users complaining about these costs.

To this end:

• [ ] Each June 30th, email all users that have not been active from the previous July 1st onwards that have a non-zero balance
• [ ] Each June 30th, lower the balance of everybody who was not active in the past 3 years (1095 days) with min(10, currentBalance)
• [ ] Inform the users of the above deduction

[SvenMokveldje]

Make sure to not check the transfer of an administrative cost as a last transfer, e.g. not writing it to the balance entity