Add roadmap management feature with database schema and user management

- Implemented roadmap.php for displaying and managing roadmap items with filters for quarter and status.
- Created schema.sql to define the database structure for users, invites, daily plans, tasks, brainstorm sessions, brainstorm cards, roadmap items, and integrations.
- Developed users.php for admin panel to manage team members and invitations, including functionality to create and revoke invites.

auth/logout.php

@@ -0,0 +1,29 @@
+<?php
+/**
+ * Fociz Uitloggen
+ */
+
+require_once __DIR__ . '/../includes/auth.php';
+start_secure_session();
+
+// Vernietig alle sessie variabelen
+$_SESSION = [];
+
+if (ini_get("session.use_cookies")) {
+    $params = session_get_cookie_params();
+    setcookie(
+        session_name(),
+        '',
+        time() - 42000,
+        $params["path"],
+        $params["domain"],
+        $params["secure"],
+        $params["httponly"]
+    );
+}
+
+session_destroy();
+
+header('Location: /auth/login.php');
+exit;
+