fixed back button with source, and customer in customer lsit clickable

frontend/src/pages/customers/CustomerForm.tsx

@@ -1,5 +1,5 @@
 import { useEffect } from 'react';
-import { useNavigate, useParams } from 'react-router-dom';
+import { useNavigate, useParams, useLocation } from 'react-router-dom';
 import { useQuery, useMutation, useQueryClient } from '@tanstack/react-query';
 import { useForm } from 'react-hook-form';
 import { customerApi } from '../../services/api';
@@ -14,8 +14,10 @@ type CustomerFormData = Omit<Customer, 'id' | 'customerNumber' | 'createdAt' | '
 export default function CustomerForm() {
   const { id } = useParams();
   const navigate = useNavigate();
+  const location = useLocation();
   const queryClient = useQueryClient();
   const isEdit = !!id;
+  const backTo = (location.state as any)?.from as string | undefined;
 
   const { register, handleSubmit, reset, watch, setValue, formState: { errors } } = useForm<CustomerFormData>();
   const customerType = watch('type');
@@ -232,7 +234,7 @@ export default function CustomerForm() {
         </Card>
 
         <div className="flex justify-end gap-4">
-          <Button type="button" variant="secondary" onClick={() => navigate(isEdit ? `/customers/${id}` : '/customers')}>
+          <Button type="button" variant="secondary" onClick={() => navigate(backTo || (isEdit ? `/customers/${id}` : '/customers'))}>
             Abbrechen
           </Button>
           <Button type="submit" disabled={isLoading}>