Sanity change history: Elevated API and API CDN errors and latency for some customers

Sanity reported a major incident affecting api.sanity.io and apicdn.sanity.io, with elevated errors, latency, and intermittent timeouts/errors on write operations and document retrieval for some customers. It started at 2026-01-15 12:23 UTC and was resolved at 2026-01-15 13:00 UTC, lasting 37 min; mitigations restored normal error rates.