Add creator role to the user Role union

src/lib/types.ts

@@ -1,4 +1,5 @@
-export type Role = "admin" | "learner";
+// creator = learner permissions + the ability to create AI-generated lessons.
+export type Role = "admin" | "learner" | "creator";
 export type Status = "pending" | "active" | "suspended";
 
 export interface User {
@@ -51,8 +52,4 @@ export function toPublicUser(u: User): PublicUser {
     level: u.level,
     status: u.status,
     email_verified: !!u.email_verified,
-    display_name: u.display_name ?? null,
-    avatar: u.avatar ?? null,
-    created_at: u.created_at,
-  };
-}
+    display_name: u.di