Portfolio readiness: improve README, demo media, and validation notes #6

Goal: make this repo look like a serious TypeScript interface project when someone clicks it from the profile.

Checklist:

• Run the app from a fresh clone and verify setup instructions are correct.
• Add a clear What this project demonstrates section.
• Add screenshots or GIFs for atlas, dashboard, explorer, compare, and methodology pages.
• Add a Data notes section that explains current project scope and limits.
• Add a Validation section describing build, lint, or typecheck commands.
• Add a short architecture note covering pages, components, data files, and UI state.
• Add 3-5 realistic roadmap items.

Definition of done:

• The README explains what exists and what is still limited.
• A reviewer can run the app and know which pages prove the work.
• The repo supports the profile story: practical TypeScript UI, data interface, and documentation discipline.