Add MessengerLog, async mailer, doctrine fixes

- MessengerLog entity: store all messenger failures with full details
- MessengerFailureSubscriber: log errors + send alert email synchronously
- MailerService: dispatch emails via Messenger bus (async)
- Makefile: add entity command
- Doctrine: enable Second Level Cache in prod, remove deprecated config
- Liip Imagine: set twig mode to lazy
- Fix app.scss @use/@import

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

Makefile

@@ -36,6 +36,10 @@ install_prod: ## Install les dependances et build les assets pour la prod
 	bun install
 	bun run build
 
+## —— Symfony ——————————————————————————————————————
+entity: ## Creer ou modifier une entite via Docker dev
+	docker compose -f docker-compose-dev.yml exec php php bin/console make:entity
+
 ## —— Database ——————————————————————————————————————
 migration_dev: ## Genere une migration via Docker dev
 	docker compose -f docker-compose-dev.yml exec php php bin/console make:migration