OptionalonCalled once if the worker pool cannot be spawned and decoding degrades to the main
thread. The layer wires this to its onError.
OptionalpoolWorker pool size. Defaults to hardwareConcurrency − 1, clamped to 1–4.
OptionalspawnFactory that creates a decode Worker (defaults to the sibling module-worker chunk).
Optionalwasmwasm load + init overrides. When wasmBytes/wasmUrl are supplied they are
forwarded to each worker; otherwise the main thread resolves a URL to forward,
and only if none is found does the worker self-init. See WasmHostInit.
Construction options for WorkerBvcGltfSplatDecoder.