Refactor configuration handling: implement dynamic loading of config and cache paths for improved security and flexibility in Docker environments

inc/load-config.php

@@ -0,0 +1,11 @@
+<?php
+declare(strict_types=1);
+
+/**
+ * Loads the site config. In Docker, FITZ_CONFIG_PATH points outside the
+ * web root (see docker-compose.yaml), so a deploy that replaces www/ can
+ * never overwrite or ship it. Local dev falls back to config.php in the
+ * project root.
+ */
+
+require getenv('FITZ_CONFIG_PATH') ?: __DIR__ . '/../config.php';