Enhance static UI and authentication: improve sidebar auth visibility, add mobile responsiveness, and refine error messages; update `/report` endpoint to use `ArticleOut` model; redesign styles for a Reddit-like layout with theming and responsive tweaks.

Remove Gradio-based UI implementation and replace it with a pure JavaScript-based static UI for articles, tips, and comments.

Add initial implementation of Yantrabodha Article API with FastAPI and Supabase integration