Export auth namespace on enhance.d.ts

packages/runtime/src/enhance.d.ts

@@ -1,2 +1,2 @@
 // @ts-expect-error stub for re-exporting generated code
-export { enhance } from '.zenstack/enhance';
+export { auth, enhance } from '.zenstack/enhance';

packages/schema/src/plugins/enhancer/enhance/auth-type-generator.ts

@@ -106,7 +106,7 @@ export function generateAuthType(model: Model, authModel: DataModel) {
     // }
     // `
 
-    return `namespace auth {
+    return `export namespace auth {
     type WithRequired<T, K extends keyof T> = T & { [P in K]-?: T[P] };
 ${Array.from(types.entries())
     .map(([model, fields]) => {