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>

.editorconfig

@@ -0,0 +1,17 @@
+# editorconfig.org
+
+root = true
+
+[*]
+charset = utf-8
+end_of_line = lf
+indent_size = 4
+indent_style = space
+insert_final_newline = true
+trim_trailing_whitespace = true
+
+[{compose.yaml,compose.*.yaml}]
+indent_size = 2
+
+[*.md]
+trim_trailing_whitespace = false