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>

config/preload.php

@@ -0,0 +1,7 @@
+<?php
+
+declare(strict_types=1);
+
+if (file_exists(dirname(__DIR__).'/var/cache/prod/App_KernelProdContainer.preload.php')) {
+    require dirname(__DIR__).'/var/cache/prod/App_KernelProdContainer.preload.php';
+}