Optimization (Docker image, JS bundle, etc.) improvements

[suzubara]

This issue may include work on some or all of the following:

• Clean up env vars & make sure they are appropriately used in the Docker builds
• Optimize packages included in dependencies (vs. devDependencies) to try and reduce image size (ie, only use bundle analyzer in development)
• Investigate tree shaking to determine if we can reduce node_modules size
• Build the Docker image as part of CI
• Report on image size & bundle size as part of CI
• Determine whether we want to go back to a single multi-stage Dockerfile for local dev & prod

Resources:

• https://github.com/nodejs/docker-node/blob/main/docs/BestPractices.md
• https://nextjs.org/docs/going-to-production
• npm prune equivalent behavior yarnpkg/yarn#696
• https://webpack.js.org/guides/tree-shaking
• https://stackoverflow.com/questions/66014730/next-js-bundle-size-is-exploding-as-a-result-of-dynamic-component-lookup-how-to
• What is the best way to use NextJS with docker? vercel/next.js#16995