Make the AWS key not public (get a new key!) and use aws on the backend instead of in the client.

[trusktr]

We currently use AWS APIs on the client side, exposing our key on the client which means anyone can take it.

We need to

• move AWS API usage to the backend
• then make a new key that is not visible on the client (tedious process that involves multiple steps to wire up multiple AWS services before finally being able to get an Identity key for the setup)

First we want to complete

• take over AWS Sumerian code so we can manage dependencies, update Three.js, to enable making new features in a scalable way. #9

so that we're in control of dependencies and all of the code (instead of relying on AWS APIs being embedded into a client-side bundle).