fix: resolve CI test failures (duplicate return, mypy dependency)

shellgenius/ollama_client.py

@@ -152,7 +152,6 @@ class OllamaClient:
                 stream=stream,
             )
             return {"success": True, "response": response}
-            return {"success": True, "response": response}
         except Exception as e:
             logger.error(f"Chat failed: {e}")
             return {"success": False, "error": str(e), "response": None}