v20 keeps v19's monochrome-hairlines-only philosophy but adds the four things v19 was missing for a real attendance app: verification-source line, tier-aware topbar chip, shift-end-in countdown, and an alert line that only appears when something is wrong (low battery, queued uploads, no GPS).
Same coral pixel budget: the live dot. Tier label sits in the existing topbar chip ("wifi" / "geo" / "gps") and replaces "live" while punched in. Verification source becomes the caption under the timer. Alert line is hidden when everything's healthy. Click the topbar chip in mid state to cycle through tiers and see how the screen reacts.