twilio-labs/dev-phone ? reverse-engineered prompt

Build me a Twilio developer tool that helps me test SMS and voice apps locally.

I want a Twilio CLI plugin that can set up the needed account resources, then start a local dev server for a companion web app. The web app should act like a phone screen where I can see incoming texts and calls, send replies, and generally test how my app behaves without using a real device. Keep the plugin and the UI working together closely, since they’re part of the same experience.

Make it easy to install and run from the Twilio CLI, and make sure the setup assumes I have my own Twilio number and an upgraded account. If you need current Twilio docs or API details, look them up online. I’d like the result to feel polished enough that someone can install it and immediately start testing SMS and Voice flows from the Dev Phone interface.