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/cache.yaml

@@ -0,0 +1,19 @@
+framework:
+    cache:
+        # Unique name of your app: used to compute stable namespaces for cache keys.
+        #prefix_seed: your_vendor_name/app_name
+
+        # The "app" cache stores to the filesystem by default.
+        # The data in this cache should persist between deploys.
+        # Other options include:
+
+        # Redis
+        #app: cache.adapter.redis
+        #default_redis_provider: redis://localhost
+
+        # APCu (not recommended with heavy random-write workloads as memory fragmentation can cause perf issues)
+        #app: cache.adapter.apcu
+
+        # Namespaced pools use the above "app" backend by default
+        #pools:
+            #my.dedicated.cache: null