* Set up and improve GitHub Codespaces support

- Create devcontainer.json for GitHub Codespaces
- Automate .env setup and port visibility settings
- Add initialization script for Codespaces
- Improve documentation for GitHub Codespaces usage
- Optimize startup process and debug logging

This consolidates multiple commits related to GitHub Codespaces
setup, automation, and documentation improvements.

* fix typo in setup script

* added missing link