List everything on the bar shelf, grouped by category.

Add one bottle, mixer, or garnish to the bar.

Call this when the user buys or acquires something, once per item. Adding something already on the shelf just updates its category.

Remove an item from the bar, because it ran out or was thrown away.

List every saved recipe with its ingredients, but without the method.

This is the cheap overview — use get_recipe for the full instructions of one drink.

Get one recipe in full, with ingredients and the method.

Save a cocktail recipe worth keeping, or update one already saved.

Delete a saved recipe.