Function assert

examples/acceptance/lttb-sample.ts:9–11

(condition: unknown, message: string)

// Intent: validate that 100K -> 1K LTTB downsampling preserves peaks/valleys.

const assert = (condition: unknown, message: string): void => {
  if (!condition) throw new Error(message);
};

// Small deterministic PRNG (Mulberry32).
function mulberry32(seed: number): () => number {