Class WorkerInitTimeoutError

Thrown when a worker's initialize() does not answer within its init deadline — as opposed to answering with a failure, or the worker dying outright. Carries the guard's label and the deadline.

Distinct from the other init failures ON PURPOSE, and for the same reason WorkerTimeoutError is excluded from isWorkerInfrastructureError below: a deadline miss does NOT establish that the worker is broken. It cannot distinguish a wedged thread from one whose reply is merely queued behind a saturated main thread — and on a large scene the second is the common case, because the Comlink reply has to be dispatched on the very thread that is busy decoding. Callers that can retry should treat this as transient; an onerror or an explicit initialize() rejection is the permanent signal.

Constructed only on the main thread (inside the init guard), so it never crosses the Comlink boundary and instanceof stays reliable.