fix(graph): 支持 codex_oauth 作为 provider 参数

添加 codex_oauth 作为有效的 provider 参数，使其与 openai 共享相同的配置逻辑

tradingagents/graph/trading_graph.py

@@ -140,7 +140,7 @@ class TradingAgentsGraph:
             if thinking_level:
                 kwargs["thinking_level"] = thinking_level
 
-        elif provider == "openai":
+        elif provider in ("openai", "codex_oauth"):
             reasoning_effort = self.config.get("openai_reasoning_effort")
             if reasoning_effort:
                 kwargs["reasoning_effort"] = reasoning_effort