seperate delivery and billig adresses in contract added

frontend/src/pages/contracts/ContractDetail.tsx

@@ -1833,9 +1833,9 @@ export default function ContractDetail() {
       )}
 
       {/* Linked Data */}
-      <div className="grid grid-cols-1 lg:grid-cols-3 gap-6 mb-6">
+      <div className="grid grid-cols-1 lg:grid-cols-4 gap-6 mb-6">
         {c.address && (
-          <Card title="Adresse">
+          <Card title="Lieferadresse">
             <CopyableBlock
               values={[
                 `${c.address.street} ${c.address.houseNumber}`,
@@ -1853,6 +1853,35 @@ export default function ContractDetail() {
             </CopyableBlock>
           </Card>
         )}
+        {/* Rechnungsadresse: Falls nicht gesetzt, Lieferadresse anzeigen */}
+        {(c.billingAddress || c.address) && (
+          <Card title="Rechnungsadresse">
+            {(() => {
+              const addr = c.billingAddress || c.address;
+              if (!addr) return null;
+              return (
+                <CopyableBlock
+                  values={[
+                    `${addr.street} ${addr.houseNumber}`,
+                    `${addr.postalCode} ${addr.city}`,
+                    addr.country
+                  ]}
+                >
+                  <p>
+                    {addr.street} {addr.houseNumber}
+                  </p>
+                  <p>
+                    {addr.postalCode} {addr.city}
+                  </p>
+                  <p className="text-gray-500">{addr.country}</p>
+                  {!c.billingAddress && c.address && (
+                    <p className="text-xs text-gray-400 mt-1">(wie Lieferadresse)</p>
+                  )}
+                </CopyableBlock>
+              );
+            })()}
+          </Card>
+        )}
         {c.bankCard && (
           <Card title="Bankkarte">
             <p className="font-medium">{c.bankCard.accountHolder}</p>