refactor : reorganize codebase to DDD architecture

Backend:
- src/Api/Auth/State/ — MeProvider, UserPasswordHasherProcessor
- src/Api/Shared/Resource/ — AppVersion
- src/Api/Shared/State/ — AppVersionProvider
- src/Domain/, src/Application/, src/Infrastructure/ — skeleton ready
- User entity stays in src/Entity/ (framework, outside DDD)

Frontend:
- frontend/domains/ — skeleton ready for bounded contexts

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/Api/Auth/State/UserPasswordHasherProcessor.php

@@ -0,0 +1,34 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Api\Auth\State;
+
+use ApiPlatform\Metadata\Operation;
+use ApiPlatform\State\ProcessorInterface;
+use App\Entity\User;
+use Symfony\Component\PasswordHasher\Hasher\UserPasswordHasherInterface;
+
+/**
+ * @implements ProcessorInterface<User, User>
+ */
+class UserPasswordHasherProcessor implements ProcessorInterface
+{
+    public function __construct(
+        /** @var ProcessorInterface<User, User> */
+        private readonly ProcessorInterface $persistProcessor,
+        private readonly UserPasswordHasherInterface $passwordHasher,
+    ) {}
+
+    public function process(mixed $data, Operation $operation, array $uriVariables = [], array $context = []): mixed
+    {
+        if ($data instanceof User && null !== $data->getPlainPassword()) {
+            $data->setPassword(
+                $this->passwordHasher->hashPassword($data, $data->getPlainPassword())
+            );
+            $data->eraseCredentials();
+        }
+
+        return $this->persistProcessor->process($data, $operation, $uriVariables, $context);
+    }
+}