Create a robust Economy system for Paper. Balance: Each player starts with 1000$. Use a HashMap to store balances. Commands: /bal: Show personal balance. /pay [player] [amount]: Transfer money to others. /eco give/set/take [player] [amount]: Admin commands (permission: eco.admin). Sell System: /sellall command. It scans inventory for DIAMOND (price: 50) and NETHERITE_INGOT (price: 500). Sum the total, add to balance, and remove items. Persistence: Save balances to 'economy.yml' every 5 minutes and on server shutdown. Messages: Use color codes (&) for all messages.