feat(script): add environment PATH cleanup tool

Introduces a PowerShell script to clean and optimize Windows PATH
variables by removing duplicates, invalid paths, and organizing
entries by category. Enhancements include backup/restore features,
detailed HTML reporting, and dry-run mode for safe previews.

Provides comprehensive logging and error handling for improved
reliability and user feedback.

Documented with extensive comments and examples for all parameters.

Author: jimbrig