remove xai_api_base stuff

agent.py

@@ -80,18 +80,6 @@ class QAgent:
                 if not api_key:
                     raise ValueError("No OpenAI API key provided. Please set Q_OAI_TOK or XAI_API_KEY environment variable or pass api_key parameter.")
             
-            # If xAI API base is available and no api_base is provided, use it
-            if xai_api_base and api_base is None:
-                api_base = xai_api_base
-                if self.verbose:
-                    print(f"Using xAI API base URL: {api_base}")
-            
-            # If no API base specified but environment variable available, use it
-            if api_base is None:
-                api_base = os.getenv("AGENT_API_BASE")
-                if api_base and self.verbose:
-                    print(f"Using API base from AGENT_API_BASE: {api_base}")
-            
             self.model = OpenAIServerModel(
                 model_id=model_id or "gpt-4o",
                 api_key=api_key,