Ably change history: Ably website, customer dashboard & Control API issues

Ably reported a critical incident affecting connectivity to ably.com, customer dashboards, the Control API (control.ably.net), the Ably blog and CMS; realtime services were unaffected. It started at 2025-12-05 08:59 UTC and was resolved at 2025-12-05 09:18 UTC, lasting 19 min.