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/league/uri-interfaces/Contracts/Conditionable.php

@@ -0,0 +1,26 @@
+<?php
+
+/**
+ * League.Uri (https://uri.thephpleague.com)
+ *
+ * (c) Ignace Nyamagana Butera <nyamsprod@gmail.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+declare(strict_types=1);
+
+namespace League\Uri\Contracts;
+
+interface Conditionable
+{
+    /**
+     * Apply the callback if the given "condition" is (or resolves to) true.
+     *
+     * @param (callable(static): bool)|bool $condition
+     * @param callable(static): (static|null) $onSuccess
+     * @param ?callable(static): (static|null) $onFail
+     */
+    public function when(callable|bool $condition, callable $onSuccess, ?callable $onFail = null): static;
+}