```typescript

type NonZeroPositiveNumber = number & { _isPositiveNonZero: true };

export function chunk<T>(items: readonly T[], size: number): T[][] {
  if (!Number.isInteger(size) || size <= 0) {
    throw new Error("Size must be a positive integer.");
  }

  const result: T[][] = [];
  for (let i = 0; i < items.length; i += size) {
    result.push(items.slice(i, i + size));
  }
  return result;
}

// Utility type to prevent zero or negative numbers
const _0_1 = (x: number): NonZeroPositiveNumber => {
  if (!Number.isInteger(x) || x <= 0) {
    throw new Error("Value must be a positive integer.");
  }
  return x as NonZeroPositiveNumber;
};
```