Configurable Currency & Level Rewards

💰 Configurable Currency & Level Rewards

• Server admins can now customize currency per server
• Default currency: Berry with strawberry emoji (🍓)
• Currency name and icon configurable in admin panel
• Level-up reward: Coins per level configurable (default: 100)
• Level-up embed now shows configured currency icon
• Shop commands use configured currency icon

🔧 Database

• New columns: level_settings.coins_per_level
• New columns: economy_settings.currency_name, economy_settings.currency_icon