Have UI be accessible to many devices

We've talked about having multiple devices access the UI for a while and we've derived a simple way to do it. Modify the web socket server URL in `main.tsx` to use the IP address of the host instead of `localhost`. Other devices can then use this IP, open a web browser and view the UI from their device. The steps required to make this as simple to use as possible:

- Modify `docker-compose.yml` to set the environment variable of IP address of host
- Modify code to use the IP address of the host from the environment variable instead of `localhost`

There will also need to be security measures implemented to ensure that only the host device can send commands but this should be implemented on the backend also using environment variables.

Start with main.tsx and docker-compose.yml to trace how the web socket URL and environment variables are configured. Verify that another device can open the UI using the host IP, and that backend command access is restricted to the host device as requested.

Written by the indexing model from the issue text.