Follow a scan in real time

A text/event-stream (Server-Sent Events) that sends the scan (the same object as GET /scans/{id}, without upload) as an event named scan at once, then every time its status, stage or error changes, and closes after the final one (complete, failed or cancelled). A ping event every 15 seconds keeps the connection alive. One stream lasts at most 30 minutes; reconnect to keep following. An account holds at most 10 streams open at once (by default): one more answers 429 with Retry-After; close one, or poll GET /scans/{id}. Needs scans:read.