feat: prepare for full ESM, replace babel-mocha env with typescript-mocha env

[davidfirst]

Summary

Optimize ESM transition by converting static imports to dynamic imports for packages that contribute significantly to bootstrap file loading.

Background

With the removal of lazy-loading in the babel -> typescript env transition, the bootstrap file count increased from ~1042 to ~2400+ files. This PR aims to reduce that count by identifying packages that:

• Have high file counts during bootstrap
• Are used in concentrated locations (easy to convert)
• Don't break type safety

Approach

Convert static imports to await import() calls for selected packages, focusing on the best effort-to-impact ratio.

Progress

• Analyze package usage and identify candidates
• Convert imports step by step, one package at a time
• Maintain proper TypeScript types (avoid any)
• Ensure functionality remains intact
• Measure file count reduction after each package

🚧 This is a draft PR for incremental development