Shadow Katana

Implement only these approved requirements: - Create a sword styled as a pure black steel katana with a black-and-purple handle, a purple eye in its center, and a shadowy aura visual appearance. - Set durability to 11, attack damage to 9, and attack speed to 10. - Apply omitted tool defaults: mining speed 6, mining level iron, enchantability 14, and the default iron repair tag. - Create the shadow_katana texture: Inventory icon of a pure black steel katana-like sword with a black and purple wrapped handle, a glowing purple eye set in the center of the handle, and a shadowy dark-purple aura around the blade.