Finanzen: Einstellungen, Rechnungen am Kunden, InvoiceNinja aus der Oberflaeche entfernt

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

src/App.jsx

@@ -10,6 +10,7 @@ import AdminPage from './pages/AdminPage'
 import CustomersPage from './pages/CustomersPage'
 import CustomerDetailPage from './pages/CustomerDetailPage'
 import FinancePage from './pages/FinancePage'
+import FinanceSettingsPage from './pages/FinanceSettingsPage'
 import LegalPage from './pages/LegalPage'
 import AssignProjectPage from './pages/AssignProjectPage'
 import ServicesPage from './pages/ServicesPage'
@@ -52,6 +53,7 @@ function AppRoutes() {
       <Route path="/leads" element={<Navigate to="/tickets" replace />} />
       {/* Finanzen: nur Admins, alle anderen gehen zu /tickets */}
       <Route path="/finance" element={<ProtectedRoute><AdminRoute><FinancePage /></AdminRoute></ProtectedRoute>} />
+      <Route path="/finance/einstellungen" element={<ProtectedRoute><AdminRoute><FinanceSettingsPage /></AdminRoute></ProtectedRoute>} />
       <Route path="/finanzen/bank-callback" element={<ProtectedRoute><AdminRoute><BankCallbackPage /></AdminRoute></ProtectedRoute>} />
       <Route path="/rechtliches" element={<ProtectedRoute><LegalPage /></ProtectedRoute>} />
       <Route path="/serverpuls" element={<ProtectedRoute><ServerpulsPage /></ProtectedRoute>} />