Add voucher-line party (تفصیل) and allow cache-control CORS headers.

Supports accounting journal detail parties and preflight from the Vite client that sends Cache-Control/Pragma.

Co-authored-by: Cursor <cursoragent@cursor.com>

accounting/serializers.py

@@ -65,10 +65,16 @@ class VoucherLineSerializer(serializers.ModelSerializer):
     # Lenient: accepts client-generated ids (ignored on write, recreated server-side).
     id = serializers.CharField(required=False)
     accountId = serializers.PrimaryKeyRelatedField(source='account', queryset=Account.objects.all())
+    partyId = serializers.PrimaryKeyRelatedField(
+        source='party',
+        queryset=Party.objects.all(),
+        required=False,
+        allow_null=True,
+    )
 
     class Meta:
         model = VoucherLine
-        fields = ['id', 'accountId', 'description', 'debit', 'credit']
+        fields = ['id', 'accountId', 'partyId', 'description', 'debit', 'credit']
 
 
 class VoucherSerializer(serializers.ModelSerializer):