feat(mail) : MailSyncRequested message + handler + messenger.yaml transport async Doctrine

- App\Message\MailSyncRequested (optionnel folderPath)
- App\MessageHandler\MailSyncRequestedHandler delegue a MailSyncService::syncFolder ou syncAll
- messenger.yaml : transport async via Doctrine DSN, retry 3x exponentiel, failure transport
- en test : transport in-memory (sync immediat)
- migration Version20260519220000 : cree messenger_messages table (idempotente, IF NOT EXISTS)

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/Message/MailSyncRequested.php

@@ -0,0 +1,12 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Message;
+
+final readonly class MailSyncRequested
+{
+    public function __construct(
+        public ?string $folderPath = null,
+    ) {}
+}

src/MessageHandler/MailSyncRequestedHandler.php

@@ -0,0 +1,54 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\MessageHandler;
+
+use App\Message\MailSyncRequested;
+use App\Repository\MailFolderRepository;
+use App\Service\MailSyncService;
+use Psr\Log\LoggerInterface;
+use Symfony\Component\Messenger\Attribute\AsMessageHandler;
+use Throwable;
+
+#[AsMessageHandler]
+final readonly class MailSyncRequestedHandler
+{
+    public function __construct(
+        private MailSyncService $mailSyncService,
+        private MailFolderRepository $folderRepository,
+        private LoggerInterface $logger,
+    ) {}
+
+    public function __invoke(MailSyncRequested $message): void
+    {
+        try {
+            if (null !== $message->folderPath) {
+                $folder = $this->folderRepository->findByPath($message->folderPath);
+                if (null !== $folder) {
+                    $report = $this->mailSyncService->syncFolder($folder);
+                    $this->logger->info(sprintf(
+                        'MailSyncRequested handled for folder "%s": %d created, %d updated, %d deleted',
+                        $message->folderPath,
+                        $report->createdCount,
+                        $report->updatedCount,
+                        $report->deletedCount,
+                    ));
+                } else {
+                    $this->logger->warning(sprintf('MailSyncRequested: folder "%s" not found in DB', $message->folderPath));
+                }
+            } else {
+                $report = $this->mailSyncService->syncAll();
+                $this->logger->info(sprintf(
+                    'MailSyncRequested handled (all folders): %d created, %d updated, %d deleted, %d folders scanned',
+                    $report->createdCount,
+                    $report->updatedCount,
+                    $report->deletedCount,
+                    $report->foldersScanned,
+                ));
+            }
+        } catch (Throwable $e) {
+            $this->logger->error('MailSyncRequestedHandler failed: '.$e->getMessage());
+        }
+    }
+}