feat(roadmaps): Hooks, Routing, Sidebar-Tab und Übersichtsseite

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/components/Navbar.jsx

@@ -9,6 +9,7 @@ import {
   IconFiles,
   IconFolders,
   IconCalendar,
+  IconRoute,
   IconLayoutDashboard,
   IconReport,
   IconDeviceDesktop,
@@ -36,6 +37,7 @@ export default function Sidebar() {
       links: [
         { label: 'Tickets', href: '/tickets', icon: <IconTicket /> },
         { label: 'Planboard', href: '/planboard', icon: <IconCalendar /> },
+        { label: 'Roadmaps', href: '/roadmaps', icon: <IconRoute /> },
         { label: 'Projekte', href: '/projects', icon: <IconFolders /> },
       ],
     },