Fix: v0.26.1 model provider (#16073)

### What problem does this PR solve?

Fix:
- Pass session_id to langfuse.
- Get correct status for add model_type.

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

test/unit_test/api/db/services/test_dialog_service_final_answer.py

@@ -140,6 +140,22 @@ class _StubRetriever:
         return answer, set()
 
 
+class _FakePropagateAttributesContext:
+    """No-op context manager for fake propagate_attributes."""
+
+    def __enter__(self):
+        return self
+
+    def __exit__(self, *args):
+        pass
+
+
+def _fake_propagate_attributes(**kwargs):
+    """Fake propagate_attributes (Langfuse v4) that records kwargs and returns a no-op context manager."""
+    _propagate_attributes_calls.append(kwargs)
+    return _FakePropagateAttributesContext()
+
+
 class _FakeLangfuseObservation:
     def __init__(self):
         self.updates = []
@@ -152,6 +168,9 @@ class _FakeLangfuseObservation:
         self.ended = True
 
 
+_propagate_attributes_calls = []
+
+
 class _FakeLangfuseClient:
     instances = []
     fail_start_observation = False
@@ -460,6 +479,8 @@ def test_async_chat_langfuse_uses_start_observation(monkeypatch):
         ),
     )
     monkeypatch.setattr(dialog_service, "Langfuse", _FakeLangfuseClient)
+    _propagate_attributes_calls.clear()
+    monkeypatch.setattr(dialog_service, "propagate_attributes", _fake_propagate_attributes)
     monkeypatch.setattr(
         dialog_service,
         "get_models",
@@ -504,6 +525,7 @@ def test_async_chat_langfuse_uses_start_observation(monkeypatch):
 @pytest.mark.p2
 def test_async_chat_langfuse_observation_includes_session_id(monkeypatch):
     _FakeLangfuseClient.instances = []
+    _propagate_attributes_calls.clear()
     monkeypatch.setattr(_FakeLangfuseClient, "fail_start_observation", False)
     chat_mdl = _StreamingChatModel("Session traces should be grouped.")
     retriever = _StubRetriever()
@@ -526,6 +548,7 @@ def test_async_chat_langfuse_observation_includes_session_id(monkeypatch):
         ),
     )
     monkeypatch.setattr(dialog_service, "Langfuse", _FakeLangfuseClient)
+    monkeypatch.setattr(dialog_service, "propagate_attributes", _fake_propagate_attributes)
     monkeypatch.setattr(
         dialog_service,
         "get_models",
@@ -553,7 +576,7 @@ def test_async_chat_langfuse_observation_includes_session_id(monkeypatch):
     assert any(e.get("final") is True for e in events)
     langfuse = _FakeLangfuseClient.instances[0]
     assert langfuse.observation_kwargs["trace_context"] == {"trace_id": "trace-id"}
-    assert langfuse.observation_kwargs["session_id"] == "session-1"
+    assert _propagate_attributes_calls[0]["session_id"] == "session-1"
 
 
 @pytest.mark.p2
@@ -629,6 +652,8 @@ def test_async_chat_continues_when_langfuse_observation_start_fails(monkeypatch)
         ),
     )
     monkeypatch.setattr(dialog_service, "Langfuse", _FakeLangfuseClient)
+    _propagate_attributes_calls.clear()
+    monkeypatch.setattr(dialog_service, "propagate_attributes", _fake_propagate_attributes)
     monkeypatch.setattr(
         dialog_service,
         "get_models",