prepare insertion of retry and assertion of login state

src/delta_barth/api/requests.py

@@ -56,6 +56,7 @@ def get_sales_prognosis_data(
     company_id: int | None = None,
     start_date: Datetime | None = None,
 ) -> tuple[SalesPrognosisResponse, Status]:
+    # TODO check elimination of assertion for login, #25
     _, status = session.assert_login()
     if status != STATUS_HANDLER.SUCCESS:
         response = SalesPrognosisResponse(daten=tuple())