Thrown when the database, its connection pool, or its network is temporarily unreachable (X35-2, M90f). The operation did not happen and may be retried.
The condition reaches the client as 503 Service Unavailable — the
load-shedding status — instead of a masked 500. No Retry-After is
carried, and the hint channel cannot carry one: ErrorResponseInit has
no header channel, and the framework holds no honest value to invent — a
pool's saturation has no published horizon. 503 is itself the retryable
signal (RFC 9110), and the rate limiter's Retry-After (which does know
its reset point) is the deliberate asymmetry, recorded in PUBLIC_API.md.
Creates the error. The message is the full diagnostic — safe to log,
never to serve.
name: string
Discriminant for consumers that cannot use instanceof across realms.