Rework user types: create AuthenticatedUser and AnonymousUser class

Both are subclasses of an abstract User class which contains almost everything
interesting.

express/database.ts

@@ -18,7 +18,7 @@ import type {
 } from "./auth/store";
 import { generateToken, hashToken } from "./auth/token";
 import type { SessionData, TokenId } from "./auth/types";
-import { User, type UserId } from "./user";
+import { AuthenticatedUser, type User, type UserId } from "./user";
 
 // Connection configuration
 const connectionConfig = {
@@ -367,7 +367,7 @@ class PostgresAuthStore implements AuthStore {
 
     // Helper to convert database row to User object
     private rowToUser(row: Selectable<UsersTable>): User {
-        return new User({
+        return new AuthenticatedUser({
             id: row.id,
             email: row.email,
             displayName: row.display_name ?? undefined,