Get current time in milliseconds (works in both Node and browser).
Node.js implementation converts hrtime bigint nanoseconds to milliseconds.
This is safe because dividing nanoseconds by 1_000_000 yields milliseconds,
which remain well below Number.MAX_SAFE_INTEGER for practical runtimes
(would take ~285 years to overflow).
Get current time in milliseconds (works in both Node and browser).
Node.js implementation converts hrtime bigint nanoseconds to milliseconds. This is safe because dividing nanoseconds by 1_000_000 yields milliseconds, which remain well below Number.MAX_SAFE_INTEGER for practical runtimes (would take ~285 years to overflow).