Create a standalone Contract Explorer server

[zachfedor]

For the "No Frontend" option, it might be nice for users to maintain access to the Contract Explorer for debugging or interacting with their contracts via the web UI. This could be done numerous ways and a spike task might be beneficial to figure out the best way forward. Options include:

• A separate package that bundles React and Vite to serve the Contract Explorer as normal
• An alternative that doesn't rely on Node with a script to parse environment variables or environments.toml to find contract addresses and load them without a bundler