fix(telegram): report cron topic fallback

cron/scheduler.py

@@ -691,6 +691,19 @@ def _deliver_result(job: dict, content: str, adapters=None, loop=None) -> Option
                                 job["id"], platform_name, chat_id, err,
                             )
                             adapter_ok = False  # fall through to standalone path
+                        elif (
+                            send_result
+                            and thread_id
+                            and getattr(send_result, "raw_response", None)
+                            and send_result.raw_response.get("thread_fallback")
+                        ):
+                            requested_thread_id = send_result.raw_response.get("requested_thread_id") or thread_id
+                            msg = (
+                                f"configured thread_id {requested_thread_id} for "
+                                f"{platform_name}:{chat_id} was not found; delivered without thread_id"
+                            )
+                            logger.warning("Job '%s': %s", job["id"], msg)
+                            delivery_errors.append(msg)
 
                 # Send extracted media files as native attachments via the live adapter
                 if adapter_ok and media_files: