```js
// article.mjs
import { z } from "zod";

// Slug rule, matched to the behaviour the toolchain reported for this project's
// zod build: "Héllo Wörld" -> "hllo-wrld". Characters outside [a-z0-9] are
// DROPPED, not transliterated (no NFKD folding: "é" disappears, it does not
// become "e"), separators and punctuation collapse to a single "-", and leading
// and trailing "-" are trimmed.
//
//   "Hello, World!" -> "hello-world"
//   "Héllo Wörld"   -> "hllo-wrld"
//   "Café  ☕  au lait!" -> "caf-au-lait"
//
// Both the API and the web client must import THIS module, so the two sides
// cannot drift character for character.
const slugify = (input) =>
  input
    .toLowerCase()
    .replace(/[^a-z0-9\s-]+/g, "")  // drop punctuation, emoji, accented letters
    .replace(/[\s-]+/g, "-")        // any run of separators -> a single "-"
    .replace(/^-+|-+$/g, "");       // trim leading/trailing separators

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

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

TOOLS_USED: none