Refactor: Replace sidebar with horizontal navigation bar

- Remove sidebar and toggle functionality
- Add Bootstrap navbar with dropdown menus
- Move navigation to top between header and content
- Update menu rendering for Bootstrap dropdowns
- Clean up unused files (header.mustache, sidebar.mustache, sidebar.js)
- Add guide link with book icon in footer
- Simplify layout structure
- Remove duplicate code and fix syntax errors
- Add .gitignore for node_modules and other temp files

vendor/composer/autoload_real.php

@@ -0,0 +1,38 @@
+<?php
+
+// autoload_real.php @generated by Composer
+
+class ComposerAutoloaderInit071586d19f5409de22b3235d85d8476c
+{
+    private static $loader;
+
+    public static function loadClassLoader($class)
+    {
+        if ('Composer\Autoload\ClassLoader' === $class) {
+            require __DIR__ . '/ClassLoader.php';
+        }
+    }
+
+    /**
+     * @return \Composer\Autoload\ClassLoader
+     */
+    public static function getLoader()
+    {
+        if (null !== self::$loader) {
+            return self::$loader;
+        }
+
+        require __DIR__ . '/platform_check.php';
+
+        spl_autoload_register(array('ComposerAutoloaderInit071586d19f5409de22b3235d85d8476c', 'loadClassLoader'), true, true);
+        self::$loader = $loader = new \Composer\Autoload\ClassLoader(\dirname(__DIR__));
+        spl_autoload_unregister(array('ComposerAutoloaderInit071586d19f5409de22b3235d85d8476c', 'loadClassLoader'));
+
+        require __DIR__ . '/autoload_static.php';
+        call_user_func(\Composer\Autoload\ComposerStaticInit071586d19f5409de22b3235d85d8476c::getInitializer($loader));
+
+        $loader->register(true);
+
+        return $loader;
+    }
+}