feat : init Central project — Symfony 8 + Nuxt 4 + Docker starter

Same architecture as Lesstime: API Platform 4, JWT auth, @malio/layer-ui,
PostgreSQL 16, Docker Compose (ports 8083/3003/5436), dark mode theme.

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

infra/dev/.env.docker

@@ -0,0 +1,9 @@
+DOCKER_APP_NAME=central
+DOCKER_PHP_VERSION=8.4.6
+DOCKER_NODE_VERSION=24.12.0
+APP_USER=www-data
+POSTGRES_DB=central
+POSTGRES_USER=root
+POSTGRES_PASSWORD=root
+POSTGRES_PORT=5436
+XDEBUG_CLIENT_HOST=host.docker.internal