Set CRM order status to PACKED after Checkbox accepts the receipt

- ExoCrmClient.set_status: live SetStatus needs {Orders: [id], Status} and
  replies per order, unlike the documented {ID, Status}
- receipts.crm_status_set_at (migration 0006); set right after creation,
  retried by cron, row-locked to avoid a repeat PACKED overwriting a newer status
- CRM errors under capitalized 'Errors' and non-JSON replies are reported

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

backend/tests/test_receipts_service.py

@@ -323,3 +323,70 @@ class TestCancel:
                 receipt.id,
                 user=None,  # type: ignore[arg-type]
             )
+
+
+class CrmSession:
+    """Фейковая сессия для sync_crm_statuses: scalars → id, scalar → строка с «блокировкой»."""
+
+    def __init__(self, *receipts: Receipt) -> None:
+        self.receipts = {r.id: r for r in receipts}
+        self.added: list[Any] = []
+        self.commits = 0
+        self.rollbacks = 0
+
+    async def scalars(self, _: Any) -> list[uuid.UUID]:
+        return [r.id for r in self.receipts.values() if r.crm_status_set_at is None]
+
+    async def scalar(self, query: Any) -> Receipt | None:
+        receipt_id = query.whereclause.clauses[0].right.value
+        receipt = self.receipts[receipt_id]
+        return receipt if receipt.crm_status_set_at is None else None
+
+    def add(self, obj: Any) -> None:
+        self.added.append(obj)
+
+    async def commit(self) -> None:
+        self.commits += 1
+
+    async def rollback(self) -> None:
+        self.rollbacks += 1
+
+
+class TestSyncCrmStatuses:
+    async def test_sets_packed_once(self) -> None:
+        from app.services.crm.stub_client import StubCrmClient
+
+        order, register = _order(), _register()
+        receipt = _pending(order, register)
+        receipt.status = ReceiptStatus.CREATED
+        session = CrmSession(receipt)
+        crm = StubCrmClient()
+
+        await svc.sync_crm_statuses(session, crm)  # type: ignore[arg-type]
+        await svc.sync_crm_statuses(session, crm)  # type: ignore[arg-type]
+
+        assert crm.statuses == {"100": "PACKED"}
+        assert receipt.crm_status_set_at is not None
+        assert session.commits == 1  # второй проход ничего не делает
+
+    async def test_crm_failure_is_retried_later(self) -> None:
+        from app.services.crm.client import CrmError
+        from app.services.crm.stub_client import StubCrmClient
+
+        order, register = _order(), _register()
+        receipt = _pending(order, register)
+        receipt.status = ReceiptStatus.CREATED
+        session = CrmSession(receipt)
+        crm = StubCrmClient()
+
+        async def broken(**_: Any) -> None:
+            raise CrmError("CRM вернула ошибку")
+
+        real_set_status = crm.set_status
+        crm.set_status = broken  # type: ignore[method-assign]
+        await svc.sync_crm_statuses(session, crm)  # type: ignore[arg-type]
+        assert receipt.crm_status_set_at is None and session.rollbacks == 1
+
+        crm.set_status = real_set_status  # type: ignore[method-assign]
+        await svc.sync_crm_statuses(session, crm)  # type: ignore[arg-type]
+        assert crm.statuses == {"100": "PACKED"}