Fix Authentication plugin v4 tutorial corrections

- Use PasswordIdentifier instead of AbstractIdentifier (constants moved in v4)
- Fix identifier config format: use className key instead of nested array
- Split code-group into separate code blocks for clarity (middleware and service)
- Fix line highlighting: {3} -> {4} for User entity import, {8} -> {9} for middleware

Author: dereuromark

docs/en/tutorials-and-examples/cms/authentication.md

@@ -45,7 +45,7 @@ Because we want to hash the password each time it is set, we'll use a mutator/se
 CakePHP will call a convention based setter method any time a property is set in one of your
 entities. Let's add a setter for the password in **src/Model/Entity/User.php**:
 
-```php {3,12-18}
+```php {4,12-18}
 <?php
 namespace App\Model\Entity;
 
@@ -109,7 +109,7 @@ In **src/Application.php**, add the following imports:
 use Authentication\AuthenticationService;
 use Authentication\AuthenticationServiceInterface;
 use Authentication\AuthenticationServiceProviderInterface;
-use Authentication\Identifier\AbstractIdentifier;
+use Authentication\Identifier\PasswordIdentifier;
 use Authentication\Middleware\AuthenticationMiddleware;
 use Psr\Http\Message\ServerRequestInterface;
 ```
@@ -123,11 +123,9 @@ class Application extends BaseApplication
 {
 ```
 
-Then add the following methods:
+Then add the following to your `middleware()` method:
 
-::: code-group
-
-```php [middleware()]
+```php
 // src/Application.php
 public function middleware(MiddlewareQueue $middlewareQueue): MiddlewareQueue
 {
@@ -142,7 +140,9 @@ public function middleware(MiddlewareQueue $middlewareQueue): MiddlewareQueue
 }
 ```
 
-```php [getAuthenticationService()]
+Next, add the `getAuthenticationService()` method:
+
+```php
 // src/Application.php
 public function getAuthenticationService(ServerRequestInterface $request): AuthenticationServiceInterface
 {
@@ -160,8 +160,8 @@ public function getAuthenticationService(ServerRequestInterface $request): Authe
     ]);
 
     $fields = [
-        AbstractIdentifier::CREDENTIAL_USERNAME => 'email',
-        AbstractIdentifier::CREDENTIAL_PASSWORD => 'password',
+        PasswordIdentifier::CREDENTIAL_USERNAME => 'email',
+        PasswordIdentifier::CREDENTIAL_PASSWORD => 'password',
     ];
 
     // Load the authenticators. Session should be first.
@@ -175,18 +175,15 @@ public function getAuthenticationService(ServerRequestInterface $request): Authe
             'action' => 'login',
         ],
         'identifier' => [
-            'Authentication.Password' => [
-                'fields' => $fields,
-            ],
+            'className' => 'Authentication.Password',
+            'fields' => $fields,
         ],
     ]);
 
     return $service;
 }
 ```
 
-:::
-
 ### Configuring the AppController
 
 In your `AppController` class add the following code: