refactor(api): update JwtAuthTokenService to use roles list in payload

Author: fulleni

lib/src/services/jwt_auth_token_service.dart

@@ -5,16 +5,6 @@ import 'package:ht_data_repository/ht_data_repository.dart';
 import 'package:ht_shared/ht_shared.dart';
 import 'package:uuid/uuid.dart';
 
-/// Helper function to convert UserRole enum to its snake_case string.
-String _userRoleToString(UserRole role) {
-  return switch (role) {
-    UserRole.admin => 'admin',
-    UserRole.standardUser => 'standard_user',
-    UserRole.guestUser => 'guest_user',
-    UserRole.premiumUser => 'premium_user',
-  };
-}
-
 /// {@template jwt_auth_token_service}
 /// An implementation of [AuthTokenService] using JSON Web Tokens (JWT).
 ///
@@ -70,9 +60,7 @@ class JwtAuthTokenService implements AuthTokenService {
           'jti': _uuid.v4(), // JWT ID (for potential blacklisting)
           // Custom claims (optional, include what's useful)
           'email': user.email,
-          'role': _userRoleToString(
-            user.role,
-          ), // Include the user's role as a string
+          'roles': user.roles, // Include the user's roles as a list of strings
         },
         issuer: _issuer,
         subject: user.id,