feat: Checklist Feature for Activity Tracking

[JustinhSE]

Overview:
Build a checklist feature so users can track which suggested activities they’ve completed. Also, implement a way for users to give feedback on activity suggestions, to improve future recommendations.

To-Do:

• Create a checklist UI in React
• Allow users to check off completed activities
• Persist checklist state (local storage or backend)
• Show progress summary
• Add thumbs up/down or rating UI to each suggestion
• Store feedback (backend)
• (Optional) Display a thank you message after feedback is submitted