```js
// NOTE: zod (v4) has no built-in string-to-slug transform — there is no `z.slug()`
// and no `.toSlug()`/`.slugify()` string method. Zod's string layer offers only
// validation plus `.trim()`, `.toLowerCase()`, `.toUpperCase()` and `.normalize()`.
// So "exactly what zod's own slug transform produces" cannot be honoured as written.
// The slug is defined explicitly here instead, in ONE place, and both the API and the
// web client must import this module so the two sides cannot drift.
import { z } from "zod";

/**
 * Deterministic slug: NFKD-normalise, drop combining marks (é -> e), lowercase,
 * collapse every run of non-alphanumerics (punctuation, spaces, emoji) to a single
 * "-", and trim leading/trailing separators.
 */
const slugify = (input) =>
  input
    .normalize("NFKD")
    .replace(/\p{M}+/gu, "")
    .toLowerCase()
    .replace(/[^a-z0-9]+/g, "-")
    .replace(/^-+|-+$/g, "");

export const Slug = z.string().transform(slugify);

export const Article = z.object({
  title: z.string().min(3),
  slug: Slug,
});
```

TOOLS_USED: none