Validates that an injected loadRequestHandler resolved to a usable
SsrRuntime, and narrows it.
Without this check a seam returning the pre-0.2.0 bare handler registers
cleanly, reports a healthy indicator, and then fails EVERY request with an
opaque 500 when the missing createLoadContext is invoked per request —
the same silent-500 class of defect this contract exists to remove. Failing
during register() turns that into one actionable startup error.
Validates that an injected
loadRequestHandlerresolved to a usableSsrRuntime, and narrows it.Without this check a seam returning the pre-0.2.0 bare handler registers cleanly, reports a healthy indicator, and then fails EVERY request with an opaque 500 when the missing
createLoadContextis invoked per request — the same silent-500 class of defect this contract exists to remove. Failing duringregister()turns that into one actionable startup error.