Summary

Add eslint-typegen integration to provide TypeScript definitions and IntelliSense for ESLint rule configurations.

Motivation

• Improve developer experience with TypeScript IntelliSense
• Provide type safety for ESLint configuration
• Reduce configuration errors through better tooling support

Dependencies

Requires ESLint v9 upgrade (#2756)

Benefits

• Full TypeScript IntelliSense for all ESLint rules
• Type safety prevents configuration errors