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/notifier.yaml

@@ -0,0 +1,12 @@
+framework:
+    notifier:
+        chatter_transports:
+        texter_transports:
+        channel_policy:
+            # use chat/slack, chat/telegram, sms/twilio or sms/nexmo
+            urgent: ['email']
+            high: ['email']
+            medium: ['email']
+            low: ['email']
+        admin_recipients:
+            - { email: admin@example.com }