Userland HTTP
Register native Effect HttpRouter, HttpApi, or RPC layers in the Layer passed to
ERSC.make({ layer }). They share the framework's HTTP server, application services, and shutdown
scope.
Register routes that require application services with HttpRouter.use, then retain those services
with Layer.provideMerge.
Native global middleware belongs in the same application Layer. It observes Page requests, Server Function requests, userland HTTP, assets, and unmatched requests. ERSC-scoped middleware has narrower reach.