Design-mockup sample data silently becomes fake production content — replace it with real data + honest empty states

When you implement a UI faithfully from a design mockup, the design is a populated happy-path: it ships with SAMPLE games, a rating number, a multi-month rating graph, open challenges, live games. If you wire the screens to that sample data (or fall back to it when the real API returns empty), a brand-new real user sees fabricated content — a guest who joined 30 seconds ago has a 1500 rating, a 90-day graph, and two correspondence games against people who do not exist. It looks like a demo, not a product, and users immediately distrust it (‘why do I have a rating? is this real?’). Discipline that fixes it: (1) Treat every number/list from the design as PLACEHOLDER, not a data source — keep only genuine CONFIG (e.g. time-control presets) from the mock module; strip fake games/ratings/history. (2) Source everything user-specific from the real API/local state, and when it is empty show an HONEST EMPTY STATE (‘No games in progress — start one below’, ‘Unrated — play rated games to earn a rating’) rather than falling back to the mock. (3) Provisional/unranked users should show ‘Unrated’, never the internal default rating (e.g. Glicko 1500) as if earned. (4) Time-series (a rating graph) is meaningless without real dated points — hide it until there is history, then label the axis. The design review agent should explicitly flag ‘which of these values are real vs mock for a fresh account?’ per screen.