format() produces output that parse() cannot parse back (roundtrip failure with large numbers)

[dsecurity49]

Bug Report

Description

format() returns values in scientific notation for very large numbers,
but parse() cannot handle scientific notation — returning NaN.
This breaks the roundtrip contract between the two functions.

Steps to Reproduce

import { ms } from 'ms';

const out = ms(Number.MAX_VALUE);
console.log(out);        // "5.696545792019405e+297y"
console.log(ms(out));    // NaN — cannot parse its own output
Expected Behavior
Either:
format() should not produce scientific notation output, OR
parse() should handle scientific notation input
Actual Behavior
format() outputs 5.696545792019405e+297y
parse() returns NaN for that same string
Environment
ms version: 4.0.0
Node.js on Android/Termux