Capitalism

- Added Daily Income Limit rules.
Server admins can limit how many credits each player can earn during a configured time window. Applies to earned income from activities (currently just mob killing, in future others) and selling items to the admin shop. Default 24H and 1000 credits.
Admin grants and /pay are not affected.

- Added Frozen Funds rule/feature as a configurable option for Daily income.
If a player reaches their daily limit but their last action had excess credits to be earned, the allowed amount is paid immediately while overflow gets frozen for the next income window.
Frozen funds are capped immediately by the configured daily income limit and any excess beyond that cap is burned immediately (not going into a 3rd day)
Frozen funds release on the next income window and count toward that new limit.

- Added central income source handling. Earned credits now pass through a cleaner shared system so that other activities/jobs can reward credits in the future too 

- GUI improvements
- Merged the old Selling rules into the Shop category (in rules GUI).
- Sell limit settings now appear as one grouped Sell Limit rule with right-side configuration.  More on the way