E-Commerce Order Management API

Build the backend API for an e-commerce platform using ASP.NET Core with Entity Framework Core and SQLite. The platform handles customers, products, and orders. Each order belongs to a customer and contains multiple order items, each referencing a product.

The API needs endpoints for:

• Listing products by category
• Viewing a single product
• Creating a new order for a customer
• Viewing order details including all items
• Listing a customer's order history

The system should handle error cases like products not found, invalid order data, and customers that don't exist. Connection details and any application settings should be configurable, not baked into the code. The app should also serve a simple static HTML page at the root.

A separate test project should accompany the main application.

Output

Produce the project under a directory called ECommerceApi/ with a test project at ECommerceApi.Tests/. Each file should contain valid C# code (correct namespaces, using statements, class/method declarations). Full business logic implementation is not required but the code structure and class skeletons should be complete.

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