All 3 tests pass. Here's a summary of what was added:

**`src/Store.cs`** — new `CreateOrderRequest` record for deserializing the request body:
```csharp
public record CreateOrderRequest(string Item, int Quantity, decimal UnitPrice);
```

**`src/Program.cs`** — new route that authenticates the caller, assigns the next available ID, persists the order, and returns 201 Created with the order in the body.

**`tests/ApiTests.cs`** — `Creating_an_order_returns_201_with_caller_as_owner` posts as alice and asserts the status code, owner, item, quantity, and unit price on the response.
