Recipe Sharing API

A cooking community wants to build a REST API where users can share and discover recipes. The system manages users, recipes, and ratings. Each recipe belongs to a user and can have multiple ratings from different users. Recipes have a title, description, list of ingredients (stored as a JSON string), preparation steps, cooking time in minutes, and a difficulty level (easy, medium, hard).

The API needs to support:

• Listing recipes with optional filtering by difficulty
• Viewing a single recipe with its average rating
• Creating a new recipe
• Rating a recipe (1-5 stars)
• Listing a user's submitted recipes

The platform runs behind a reverse proxy in production. Database and application configuration (such as the maximum number of recipes returned per page) should come from configuration files rather than being hardcoded. The app should also serve a simple static HTML frontend. A test project should be included.

Output

Produce the project under RecipeApi/ with tests at RecipeApi.Tests/. Each file should contain valid C# code with correct namespaces and complete class skeletons. Full business logic is not required but the structure and type definitions should be complete.

Include a project-structure.txt file at the root listing the directory tree.