feat(js): add bun build & bun tests

[vobradovich]

No description provided.

[gemini-code-assist]

Code Review

This pull request implements a Bun-based build and test system across the project, adding specialized build scripts for multiple packages and updating package configurations. It also introduces a test setup utility and enhances test reliability with improved cleanup logic. Review feedback suggests using more robust regex for import replacements, adding validation for configuration-based URLs, and avoiding source file modifications during the build process to prevent side effects.