Refactor LLM route-first provider API (#28523)

packages/llm/src/route/index.ts

@@ -1,14 +1,13 @@
-export { Route, LLMClient, modelLimits, modelRef } from "./client"
+export { Route, LLMClient } from "./client"
 export type {
   Route as RouteShape,
-  RouteModelDefaults,
   RouteModelInput,
-  RouteRoutedModelDefaults,
   RouteRoutedModelInput,
+  RouteDefaults,
+  RouteDefaultsInput,
   AnyRoute,
   Interface as LLMClientShape,
   Service as LLMClientService,
-  ModelRefInput,
 } from "./client"
 export * from "./executor"
 export { Auth } from "./auth"