feat: notification system via Mercure for scraping events

- NotificationInterface: add sendInfo() and sendWarning() levels
- SymfonyNotification: implement new levels (publishes to 'notifications' topic)
- ChapterScrapingStarted: carry mangaTitle + chapterNumber, now dispatched
- ScrapeChapterHandler: dispatch ChapterScrapingStarted before scraping loop
- ScrapingEventSubscriber: wire NotificationInterface for started/scraped/failed events
- useMercureNotifications: new global Vue composable subscribing to 'notifications' topic
- App.vue: mount useMercureNotifications() at app root
- SendTestNotificationCommand: `app:notify:test --type --message` for dev/prod testing

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/Domain/Scraping/Application/CommandHandler/ScrapeChapterHandler.php

@@ -11,6 +11,7 @@ use App\Domain\Scraping\Domain\Contract\Service\ImageDownloaderInterface;
 use App\Domain\Scraping\Domain\Contract\Service\ScraperFactoryInterface;
 use App\Domain\Shared\Domain\Event\ChapterScraped;
 use App\Domain\Scraping\Domain\Event\ChapterScrapingFailed;
+use App\Domain\Scraping\Domain\Event\ChapterScrapingStarted;
 use App\Domain\Scraping\Domain\Model\Chapter;
 use App\Domain\Scraping\Domain\Model\ScrapingJob;
 use App\Domain\Scraping\Domain\Model\Source;
@@ -53,13 +54,16 @@ readonly class ScrapeChapterHandler
                 throw new \InvalidArgumentException("Manga not found with ID: {$chapter->mangaId}");
             }
 
-            // 3. Détermination des sources à utiliser
+            // 3. Dispatch de l'événement de démarrage
+            $this->eventBus->dispatch(new ChapterScrapingStarted($manga->getTitle(), $chapter->chapterNumber));
+
+            // 4. Détermination des sources à utiliser
             $sources = $this->getSourcesToTry($manga);
             if (empty($sources)) {
                 throw new \InvalidArgumentException("No sources available for scraping");
             }
 
-            // 4. Essai de scraping sur chaque source jusqu'à succès
+            // 5. Essai de scraping sur chaque source jusqu'à succès
             $success = false;
             $lastException = null;