OA: Recipe manager with versions

Build RecipeManager, an in-memory store of recipes. Each recipe has an id, a display name and a list of ingredient strings.

Recipe names are unique ignoring case: "Pancakes" and "PANCAKES" can't both exist. Keep the name exactly as it was given, though; only comparisons ignore case.

• add_recipe(recipe_id, name, ingredients) -> bool: store a new recipe. False (and nothing changes) if the id is already used or another recipe already has that name (ignoring case).
• get_recipe(recipe_id) -> dict | None: {"id": ..., "name": ..., "ingredients": [...]} for the recipe, or None if there's no such recipe.
• update_recipe(recipe_id, name, ingredients) -> bool: replace the name and ingredients. False if the recipe doesn't exist or the new name belongs to a different recipe. A recipe may keep its own name (in any casing).
• delete_recipe(recipe_id) -> bool: False if there's no such recipe. A deleted recipe's id and name become free again.

The store must not share list objects with callers: changing a list you passed in, or one you got back, must not change the stored recipe.

m = RecipeManager()
m.add_recipe("7", "Tomato Soup", ["tomato", "salt"])   # True
m.add_recipe("8", "tomato soup", ["tomato"])           # False: name taken
m.update_recipe("7", "TOMATO SOUP", ["tomato"])        # True: its own name
m.get_recipe("7")      # {"id": "7", "name": "TOMATO SOUP", "ingredients": ["tomato"]}
m.delete_recipe("7")   # True
m.add_recipe("8", "tomato soup", ["tomato"])           # True now

Aim for O(1) name checks; the store may hold tens of thousands of recipes.