What to try — b3-trial-sentinel

# WHAT TO TRY — B3 Trial Sentinel ("Sentinel Slate")

Open `index.html` in any modern browser (double-click the file, or serve the folder). No install, **no account, no bank anything** — that's printed on the page and it's literally true: the file makes no network calls.

1. **Look at the 3 SAMPLE trials already on watch.** They're invented, labeled **SAMPLE** on every card, and dated relative to today on purpose: one flags **T-0** (ends today), one flags **T-2** (ends in 2 days), one is calm at 9 days. The badges were computed when you opened the page, against today's real date.
2. **Read the summary:** "Everything I pay for" totals **$39.97/month** with the samples in (14.99 + 14.99 + 9.99). Remember that number for step 5.
3. **Try to cheat the form:** add a trial and leave the **cancellation path** blank. It refuses, and tells you why — that field is the product's soul. Fill in name, date, and price only after.
4. **Add a real trial of your own** with an end date 2 days from today. It should appear with a **T-2** badge, sorted by end date, and the monthly total should rise by exactly its price.
5. **Remove the 3 SAMPLE trials**, one by one. The total drops each time and lands on just your own entries. Reload the page — the samples do **not** come back, and your trial is still there (that's localStorage, on this device only).
6. **Reload on a different day** (or just trust the fixture): badges recompute on every open. Nothing runs in the background — a closed page cannot buzz you, and the footer says so instead of promising it.

The real test this prototype is staging for: one household's real subscription list, entered live at signup-time for a month. That run is a separate commission.