Experience optimization

Optimization: Switching from single-player to multiplayer mode, and becoming a King without consuming a crown.
Value Adjustment: Debt collection letters will no longer be generated when the player has no deposit.
Optimization: The barracks supply list can now hide low-level weapons and equipment.
Optimization: Research can now directly use bank deposits.
Bug Fix: The bottom frame of the merchant item preview on the trading desk was missing and displayed as pure white.