Add roadmap management, service worker, and user invitation features

- Implemented roadmap.php for managing roadmap items with filtering options by quarter and status.
- Added a service worker (sw.js) to handle push notifications and click events for calendar appointments.
- Created users.php for admin to manage team members and invitations, including user creation and deletion functionalities.

includes/footer.php

@@ -0,0 +1,26 @@
+</main>
+
+<footer class="border-t border-slate-200/80 dark:border-slate-800/60 bg-white/40 dark:bg-transparent backdrop-blur-sm py-5 text-center text-xs text-slate-500 transition">
+    <div class="max-w-7xl mx-auto px-4 sm:px-6 lg:px-8 flex flex-col sm:flex-row items-center justify-between gap-2">
+        <div class="flex items-center space-x-2">
+            <span class="font-bold text-slate-800 dark:text-slate-300">Fociz</span>
+            <span>&bull;</span>
+            <span class="text-slate-500 dark:text-slate-400">Focus & Structuur Systeem</span>
+        </div>
+        <div>
+            <span class="text-slate-400 dark:text-slate-500">Beveiligd met MariaDB & Tweestapsverificatie (2FA)</span>
+        </div>
+    </div>
+</footer>
+
+<!-- Fociz Agenda Notificaties Engine -->
+<script src="/assets/js/notifications.js"></script>
+
+<script>
+    // Lucide Icons initialiseren
+    if (typeof lucide !== 'undefined') {
+        lucide.createIcons();
+    }
+</script>
+</body>
+</html>