Money arithmetic with allocation

Implement money.ts exporting a Money class for exact currency math using integer minor units. Money.of(amount: string | number, currency: string) parses like "19.99" (reject more decimals than the currency allows; USD and EUR have 2, JPY has 0, KWD has 3). Methods: add, subtract (throw on currency mismatch), multiply(factor: number, rounding: "half-even"), allocate(ratios: number[]): Money[] that splits without losing or creating a cent (remainders distributed to earliest parts), format(locale) using Intl, toJSON() returning {amount: string, currency}, and compare. Immutable. No floating point in stored state. No dependencies. Return only the file in one code block.