fix: resolve missing serialized kwargs in PatchedChatDeepSeek (#2025)

* add tests

* fix ci

* fix ci

backend/packages/harness/deerflow/models/openai_codex_provider.py

@@ -48,6 +48,10 @@ class CodexChatModel(BaseChatModel):
 
     model_config = {"arbitrary_types_allowed": True}
 
+    @classmethod
+    def is_lc_serializable(cls) -> bool:
+        return True
+
     @property
     def _llm_type(self) -> str:
         return "codex-responses"

backend/packages/harness/deerflow/models/patched_deepseek.py

@@ -23,6 +23,14 @@ class PatchedChatDeepSeek(ChatDeepSeek):
     request payload.
     """
 
+    @classmethod
+    def is_lc_serializable(cls) -> bool:
+        return True
+
+    @property
+    def lc_secrets(self) -> dict[str, str]:
+        return {"api_key": "DEEPSEEK_API_KEY", "openai_api_key": "DEEPSEEK_API_KEY"}
+
     def _get_request_payload(
         self,
         input_: LanguageModelInput,