Implemented multiply helper per TEST-002 inside `src/utils/multiply.ts:1` with typed signature, descriptive JSDoc, and inline note clarifying the straightforward arithmetic approach:

```typescript
src/utils/multiply.ts
/**
 * Multiplies two numeric operands using JavaScript's built-in arithmetic.
 * @param a First factor.
 * @param b Second factor.
 * @returns Product of `a` and `b`.
 */
export function multiply(a: number, b: number): number {
  // Basic arithmetic multiply to satisfy TEST-002.
  return a * b;
}
```

Let me know if you’d like tests wired up or this exported elsewhere.