feat: optimized env shim & support object.keys

[tada5hi]

🔗 Linked issue

resolves #118

❓ Type of change

• 📖 Documentation (updates to the documentation, readme, or JSdoc annotations)
• 🐞 Bug fix (a non-breaking change that fixes an issue)
• 👌 Enhancement (improving an existing functionality like performance)
• ✨ New feature (a non-breaking change that adds functionality)
• 🧹 Chore (updates to the build process or auxiliary tools and libraries)
• ⚠️ Breaking change (fix or feature that would cause existing functionality to change)

📚 Description

📝 Checklist

• I have linked an issue or discussion.
• I have updated the documentation accordingly.

[tada5hi]

@pi0 how can i help to move this forward ?

[pi0]

Thanks for PR. It looks nice but too many changes in one PR that I need to carefully review. (https://github.com/pi0/tired-maintainer)

[tada5hi]

@pi0 you are very welcome ☺️✌️. I know you have much on your plate. This pr is also not urgent. So if I can help you any further or should adjust something, please let me know (ping me).