Four project-wide documents — PRD, Feature catalog, Design spec, and Build plan. Each is filterable by app scope (Designer / Host / Client / Remote / project-wide).
Cross-cutting source of truth across the whole platform — each doc carries scope chips so a reader can filter visually for Designer / Host / Client / Remote.
Product Requirements — what the platform does, the user experience, the functional requirements that have to land.
Every feature shipped, in progress, or planned — high-level capabilities with sub-features one click away.
Single source for brand identity, design tokens, and the four per-app design languages — Designer, Host, Remote, Client — plus a Comparison matrix.
Live implementation checklist — every concrete piece of work, tagged by phase and app.