PFC 2.0 web foundation

Phase 2

Phase 2 skeleton — app shell + design system. No real pages yet.

This is the foundation, not a page

WP-2.1 (scaffold + gunicorn + health) and WP-2.3 (design system)

The Streamlit app at the repo root is untouched. Every future page is built only from components documented on the styleguide.
Open the styleguide Health check