fix: preserve long prosecutor authority names

tests/apps/exchange/test_api.py

@@ -489,6 +489,7 @@ class ExchangePackageApiTest(APITestCase):
             response.data["result"]["financial_reports"]["created_lines"],
             1,
         )
+
         self.assertEqual(
             response.data["result"]["defense_unreliable_suppliers"]["created"],
             1,
@@ -535,6 +536,25 @@ class ExchangePackageApiTest(APITestCase):
         self.assertEqual(package_import.delivery_channel, ExchangeDeliveryChannel.API)
         self.assertEqual(package_import.status, "success")
 
+    def test_upload_preserves_long_prosecutor_control_authority(self):
+        payload = build_exchange_payload()
+        long_authority = "Межрегиональное контрольное управление " + "А" * 300
+        payload["prosecutor_checks"][0]["control_authority"] = long_authority
+        archive = build_exchange_archive(data=payload)
+
+        response = self.client.post(
+            self.url,
+            {"file": archive},
+            format="multipart",
+            HTTP_X_EXCHANGE_TOKEN=TEST_TOKEN,
+        )
+
+        self.assertEqual(response.status_code, status.HTTP_201_CREATED)
+        self.assertEqual(
+            ProsecutorCheck.objects.get().control_authority,
+            long_authority,
+        )
+
     def test_upload_rejects_invalid_exchange_token(self):
         archive = build_exchange_archive(data=build_exchange_payload())
         invalid_token = get_random_string(24)