Databook

Replaced the approximated navigation and footer with the exact production markup and CSS from databook.nyc. Added the databook design tokens stylesheet, updated SiteNav with the canonical nine-link header and mobile drawer, and implemented the exact five-column footer layout.

Corrects the Phase 2 specification to reflect that NYCDB is a read-only DuckDB file rather than Postgres. Updates documentation regarding engine notes, query placeholders, value-casing, and connected-components implementation.

Added documentation for the Phase 3 landlord corporate-record card using NYS DOS data. The spec outlines loading active corporations, establishing a SQL-measured match rate gate before building the frontend, and details the proposed API endpoint and data caveats.

This pull request adds a new "Ownership & portfolio" section to building pages and introduces a new landlord route. These features consume new API endpoints to display landlord cards, associated buildings, portfolio maps, and trend sparklines, degrading gracefully with a "not available yet" state until the backend endpoints go live.

Added documentation for the Phase 2 Databook-box data and endpoint specifications. This includes details on the HPD Registration Contacts join chain, portfolio grouping logic, and new endpoints for building landlord and portfolio data.

Added headline accountability chips for open HPD violations, total violations, evictions, and rent-stabilized status to the building profile page. The new chips dynamically color-code based on status and gracefully handle pending API updates for open violation metrics.