CMS 2.0 - Theme engine, logging, admin improvements

Major changes:
- New ThemeManager with Twig templating and SCSS compilation
- Dynamic themes system (themes/default, themes/demo)
- LogManager with SQLite storage and syslog forwarding
- RequestLogger with static helper methods
- Admin UI overhaul (Bootstrap 5, dark mode)
- Admin config page with logging and theme settings
- Admin logs page with filters and search
- Removed legacy Mustache templates
- Removed test plugin and theme
- Composer dependencies: Twig, scssphp, CommonMark, MaxMind GeoIP

vendor/maxmind/web-service-common/src/Exception/PermissionRequiredException.php

@@ -0,0 +1,12 @@
+<?php
+
+declare(strict_types=1);
+
+namespace MaxMind\Exception;
+
+/**
+ * This exception is thrown when the service requires permission to access.
+ */
+class PermissionRequiredException extends InvalidRequestException
+{
+}