Web SDK: gRPC-web proxy for local installs

## Summary

Replace the current gRPC+web setup with a gRPC proxy for web client local installs, simplifying the infrastructure requirements for local development.

Look at the current gRPC+web setup in the codebase to understand the existing infrastructure. Identify where the proxy needs to be implemented and how it integrates with local development. Check for any existing configuration or examples of gRPC-web proxies in the project. Determine the entry points for web client local installs and what 'done' looks like in terms of simplified local development requirements.

Written by the indexing model from the issue text.