fix: connect all new pages to router + navigation + backend API routes (Workstream, Wiki, Improvement, Onboarding, Dashboard, DSGVO), platform.py with 9 endpoints, tsc clean

frontend/src/pages/Onboarding.tsx

@@ -0,0 +1,26 @@
+/**
+ * OnboardingPage — Route wrapper for SetupWizard component.
+ * Renders the SetupWizard as a full-page dialog.
+ */
+
+import React, { useCallback } from 'react';
+import { useNavigate } from 'react-router-dom';
+import { SetupWizard } from '@/components/onboarding/SetupWizard';
+
+export function OnboardingPage() {
+  const navigate = useNavigate();
+
+  const handleClose = useCallback(() => {
+    navigate('/dashboard');
+  }, [navigate]);
+
+  const handleComplete = useCallback(() => {
+    navigate('/dashboard');
+  }, [navigate]);
+
+  return (
+    <SetupWizard open={true} onClose={handleClose} onComplete={handleComplete} />
+  );
+}
+
+export default OnboardingPage;