refactor: preserve some next-auth v4 functionality (#9617)

* refactor: drop `types` submodule

* refactor: drop `@internal` from `getCsrfToken` and `getProviders`

* refactor: re-export types from `@auth/core`

* refactor: re-export `@auth/core/jwt`

Author: balazsorban44

packages/next-auth/package.json

@@ -40,9 +40,6 @@
       "types": "./react.d.ts",
       "import": "./react.js"
     },
-    "./types": {
-      "types": "./types.d.ts"
-    },
     "./package.json": "./package.json"
   },
   "keywords": [

packages/next-auth/src/index.tsx

@@ -66,12 +66,12 @@ import type { NextAuthConfig, NextAuthRequest } from "./lib/index.js"
 export { AuthError } from "@auth/core/errors"
 
 export type {
+  Session,
   Account,
-  DefaultSession,
   Profile,
-  Session,
+  DefaultSession,
   User,
-} from "./types.js"
+} from "@auth/core/types"
 
 type AppRouteHandlers = Record<
   "GET" | "POST",

packages/next-auth/src/jwt.ts

@@ -1,16 +1,9 @@
 /**
- * :::warning Deprecated
- * This module is replaced in v5. Read more at: https://authjs.dev/guides/upgrade-to-v5#authenticating-server-side
+ * :::warning Not recommended
+ * In NextAuth.js v5 or newer, we recommend other authentication methods server-side. Read more at: https://authjs.dev/guides/upgrade-to-v5#authenticating-server-side
  * :::
  *
  * @module jwt
  */
 
-throw new ReferenceError(
-  [
-    '"next-auth/jwt" is deprecated. If you are not ready to migrate, keep using "next-auth@4".',
-    "Read more on https://authjs.dev/guides/upgrade-to-v5",
-  ].join("\n")
-)
-
-export {}
+export * from "@auth/core/jwt"

packages/next-auth/src/react.tsx

@@ -184,7 +184,6 @@ export async function getSession(params?: GetSessionParams) {
  * required to make requests that changes state. (e.g. signing in or out, or updating the session).
  *
  * [CSRF Prevention: Double Submit Cookie](https://cheatsheetseries.owasp.org/cheatsheets/Cross-Site_Request_Forgery_Prevention_Cheat_Sheet.html#double-submit-cookie)
- * @internal
  */
 export async function getCsrfToken() {
   const response = await fetchData<{ csrfToken: string }>(
@@ -203,7 +202,6 @@ type ProvidersType = Record<
 /**
  * Returns a client-safe configuration object of the currently
  * available providers.
- * @internal
  */
 export async function getProviders() {
   return fetchData<ProvidersType>("providers", __NEXTAUTH, logger)