feat(activity): mises à jour temps réel des jobs via Mercure

- Ajoute jobId dans ChapterScrapingStarted et ChapterScrapingFailed
- Publie job.created (PENDING) depuis ScrapeChapterStateProcessor
- Publie job.status_changed (in_progress/completed/failed) depuis ScrapingEventSubscriber
- Gère job.created et job.status_changed dans activityStore : ajout instantané et suppression différée (1.5s)

tests/Domain/Scraping/Application/CommandHandler/ScrapeChapterHandlerTest.php

@@ -78,6 +78,7 @@ class ScrapeChapterHandlerTest extends TestCase
         $this->assertCount(2, $dispatchedMessages);
 
         $this->assertInstanceOf(ChapterScrapingStarted::class, $dispatchedMessages[0]);
+        $this->assertSame($jobId, $dispatchedMessages[0]->getJobId());
         $this->assertSame(2.0, $dispatchedMessages[0]->getChapterNumber());
 
         $this->assertInstanceOf(ChapterScraped::class, $dispatchedMessages[1]);