fix(telegram): report cron topic fallback

tests/cron/test_scheduler.py

@@ -2396,6 +2396,65 @@ class TestDeliverResultTimeoutCancelsFuture:
         assert result is None, f"expected successful delivery, got error: {result!r}"
         standalone_send.assert_awaited_once()
 
+    def test_live_adapter_thread_fallback_records_delivery_error(self):
+        """A cron target with an explicit topic must not be marked clean if
+        Telegram falls back to the base chat after "thread not found".
+        """
+        from gateway.config import Platform
+        from gateway.platforms.base import SendResult
+        from concurrent.futures import Future
+
+        send_result = SendResult(
+            success=True,
+            message_id="42",
+            raw_response={
+                "requested_thread_id": 7072,
+                "thread_fallback": True,
+            },
+        )
+        adapter = MagicMock()
+        adapter.send = AsyncMock(return_value=send_result)
+
+        pconfig = MagicMock()
+        pconfig.enabled = True
+        mock_cfg = MagicMock()
+        mock_cfg.platforms = {Platform.TELEGRAM: pconfig}
+
+        loop = MagicMock()
+        loop.is_running.return_value = True
+
+        job = {
+            "id": "thread-fallback-job",
+            "deliver": "telegram:226252250:7072",
+        }
+
+        completed_future = Future()
+        completed_future.set_result(send_result)
+
+        def fake_run_coro(coro, _loop):
+            coro.close()
+            return completed_future
+
+        with patch("gateway.config.load_gateway_config", return_value=mock_cfg), \
+             patch("cron.scheduler.load_config", return_value={"cron": {"wrap_response": False}}), \
+             patch("asyncio.run_coroutine_threadsafe", side_effect=fake_run_coro):
+            result = _deliver_result(
+                job,
+                "Hello world",
+                adapters={Platform.TELEGRAM: adapter},
+                loop=loop,
+            )
+
+        assert result == (
+            "configured thread_id 7072 for telegram:226252250 was not found; "
+            "delivered without thread_id"
+        )
+        adapter.send.assert_called_once_with(
+            "226252250",
+            "Hello world",
+            metadata={"thread_id": "7072"},
+        )
+
 
 class TestSendMediaTimeoutCancelsFuture:
     """Same orphan-coroutine guarantee for _send_media_via_adapter's

tests/gateway/test_telegram_thread_fallback.py

@@ -372,7 +372,7 @@ async def test_send_typing_falls_back_without_thread_on_bad_request():
 
 @pytest.mark.asyncio
 async def test_send_retries_without_thread_on_thread_not_found():
-    """When message_thread_id causes 'thread not found', retry without it."""
+    """When message_thread_id keeps failing, retry once then fall back."""
     adapter = _make_adapter()
 
     call_log = []
@@ -394,10 +394,43 @@ async def test_send_retries_without_thread_on_thread_not_found():
 
     assert result.success is True
     assert result.message_id == "42"
-    # First call has thread_id, second call retries without
+    assert result.raw_response["requested_thread_id"] == 99999
+    assert result.raw_response["thread_fallback"] is True
+    # First two calls keep the configured thread, then final fallback drops it.
+    assert len(call_log) == 3
+    assert call_log[0]["message_thread_id"] == 99999
+    assert call_log[1]["message_thread_id"] == 99999
+    assert call_log[2]["message_thread_id"] is None
+
+
+@pytest.mark.asyncio
+async def test_send_retries_transient_thread_not_found_before_fallback():
+    """A one-off Telegram thread-not-found response should still land in the topic."""
+    adapter = _make_adapter()
+
+    call_log = []
+
+    async def mock_send_message(**kwargs):
+        call_log.append(dict(kwargs))
+        if len(call_log) == 1:
+            raise FakeBadRequest("Message thread not found")
+        return SimpleNamespace(message_id=43)
+
+    adapter._bot = SimpleNamespace(send_message=mock_send_message)
+
+    result = await adapter.send(
+        chat_id="123",
+        content="test message",
+        metadata={"thread_id": "99999"},
+    )
+
+    assert result.success is True
+    assert result.message_id == "43"
+    assert result.raw_response["requested_thread_id"] == 99999
+    assert result.raw_response["thread_fallback"] is False
     assert len(call_log) == 2
     assert call_log[0]["message_thread_id"] == 99999
-    assert call_log[1]["message_thread_id"] is None
+    assert call_log[1]["message_thread_id"] == 99999
 
 
 @pytest.mark.asyncio
@@ -1079,6 +1112,7 @@ async def test_send_without_thread_id_unaffected():
     )
 
     assert result.success is True
+    assert result.raw_response["thread_fallback"] is False
     assert len(call_log) == 1
     assert call_log[0]["message_thread_id"] is None