How to add an endpoint filter to a minimal API in ASP.NET Core 11
A complete, working guide to endpoint filters in an ASP.NET Core 11 minimal API: AddEndpointFilter with an inline delegate, IEndpointFilter classes with DI, GetArgument and the Arguments list, short-circuiting with Results.Problem, FIFO/FILO ordering across multiple filters, group-level filters on MapGroup, and AddEndpointFilterFactory for signature-aware filters.