setTimeout and setInterval passed their delay to the F64 timer slot
unconverted, so a delay typed number | undefined failed with SC2003. Such
a delay is an optional `ms?: number` passed on, or a number[] element
read, whose storage keeps the out-of-range undefined. Node converts the
delay with ToNumber, so undefined is NaN, the omitted delay. A union
delay now goes through lowerOptionalNumber, as Math arguments already
do. Other unions still reach the lib boundary's refusal, and number
delays are unchanged.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>