feat(story-1.1): scaffold Symfony 7.4 LTS app with DDEV, Messenger, Scheduler

- DDEV config: PHP 8.4, PostgreSQL 16, nginx-fpm, Imagick via webimage_extra_packages
- Symfony 7.4 LTS skeleton + webapp pack scaffolded via Composer
- Removed AssetMapper, Stimulus, UX-Turbo (replaced by Vue 3 SPA per architecture)
- Added symfony/messenger + symfony/scheduler (Doctrine transport)
- Gitea CI workflow: PHP 8.4 container + PostgreSQL 16 service, runs phpunit

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

config/packages/messenger.yaml

@@ -0,0 +1,26 @@
+framework:
+    messenger:
+        failure_transport: failed
+
+        transports:
+            # https://symfony.com/doc/current/messenger.html#transport-configuration
+            async:
+                dsn: '%env(MESSENGER_TRANSPORT_DSN)%'
+                retry_strategy:
+                    max_retries: 3
+                    multiplier: 2
+            failed: 'doctrine://default?queue_name=failed'
+            # sync: 'sync://'
+
+        default_bus: messenger.bus.default
+
+        buses:
+            messenger.bus.default: []
+
+        routing:
+            Symfony\Component\Mailer\Messenger\SendEmailMessage: async
+            Symfony\Component\Notifier\Message\ChatMessage: async
+            Symfony\Component\Notifier\Message\SmsMessage: async
+
+            # Route your messages to the transports
+            # 'App\Message\YourMessage': async