Tesla just might be viewed more as a robotics stock than an electric vehicle stock someday.Tesla (TSLA 0.43%) released part four of its "master plans" recently -- and there was a twist. The company's first master plan document dates back to August 2006. That document focused on electric vehicles. The next two parts included electricity generation and storage. However, Tesla's latest master plan update mentioned the company's Optimus humanoid robot for the first time. CEO Elon Musk responded earlier this mon ...