How to launch and drive the devcon website to verify UI changes at runtime (dev server + headless Chromium via playwright-core).
How to handle "current time" in the event-app (the Devcon PWA under event-app/). Use whenever building or changing time-dependent UI — schedule live/upcoming status, countdowns, the room-screen clock, "happening now" badges, relative times, which day to highlight, etc. All such code must read the current time from the shared `useNow`/`useNowMs` hook (never `Date.now()` / `new Date()` directly in a component), so it can be mocked via URL query params (`?mockNow=`, `?mockSpeed=`) for testing date-specific flows — the same pattern devcon.org uses. Triggers: "now", "current time", "countdown", "live/upcoming", "relative time", "today", "mock time", "test the date", "schedule status", "clock".
How to add or change state/data persistence in the event-app (the offline-first Devcon PWA under event-app/). Use whenever adding a data-fetching hook, caching API responses, persisting user state, or deciding where state lives in event-app. The app is offline-first: all persisted state must go through the Dexie/IndexedDB-backed SWR layer so it survives no connectivity. Triggers: "fetch X in event-app", "cache", "offline", "persist", "store", "useSWR", "Dexie", "IndexedDB", "add a hook", "state management".
Postgres performance optimization and best practices from Supabase. Use this skill when writing, reviewing, or optimizing Postgres queries, schema designs, or database configurations.