added backup and email client

frontend/src/pages/contracts/ContractDetail.tsx

@@ -2,6 +2,7 @@ import { useState, useEffect } from 'react';
 import { useParams, Link, useNavigate, useLocation } from 'react-router-dom';
 import { useQuery, useMutation, useQueryClient } from '@tanstack/react-query';
 import { contractApi, uploadApi, meterApi, contractTaskApi, appSettingsApi } from '../../services/api';
+import { ContractEmailsSection } from '../../components/email';
 import { useAuth } from '../../context/AuthContext';
 import Card from '../../components/ui/Card';
 import Button from '../../components/ui/Button';
@@ -2326,6 +2327,14 @@ export default function ContractDetail() {
         isCustomerPortal={isCustomerPortal}
       />
 
+      {/* Zugeordnete E-Mails */}
+      {!isCustomerPortal && hasPermission('contracts:read') && c.customerId && (
+        <ContractEmailsSection
+          contractId={contractId}
+          customerId={c.customerId}
+        />
+      )}
+
       {c.notes && (
         <Card title="Notizen">
           <p className="whitespace-pre-wrap">{c.notes}</p>

frontend/src/pages/contracts/ContractForm.tsx

@@ -142,6 +142,17 @@ export default function ContractForm() {
     }
   }, [isEdit]);
 
+  // Set preselected customer from URL params (for new contracts)
+  useEffect(() => {
+    if (!isEdit && preselectedCustomerId && customersData?.data) {
+      // Only set if the customer exists in the list
+      const customerExists = customersData.data.some(c => c.id.toString() === preselectedCustomerId);
+      if (customerExists) {
+        setValue('customerId', preselectedCustomerId);
+      }
+    }
+  }, [isEdit, preselectedCustomerId, customersData, setValue]);
+
   // Reset tariffId when providerId changes (but only after initial contract load)
   useEffect(() => {
     // Only reset tariff if: