Registers this browser as a device on your Notibase, then you fire a
push at it from your terminal. Client key in the page, server key in the
terminal — the publishable-key model, demonstrated.
1 · Paste credentials (from bootstrap.js output; saved locally in this browser)
2 · Subscribe this browser
3 · Send yourself a push — run this in any terminal
Replace sk_live_... with your SERVER key. The notification
should appear even if you close this tab — that's the service worker doing
its job. Then check the delivery log: