Slug generator

Turns a title into a URL slug: accents folded to plain letters, everything lowercased, and every run of non-alphanumeric characters replaced with a single hyphen.

Folding accents rather than percent-encoding them is the right call for URLs even though modern browsers handle Unicode fine. An encoded URL is unreadable when copied into plain text, breaks when a system truncates it, and is easy to typo — "café" becomes "caf%C3%A9" in an email. Two conventions worth following: hyphens rather than underscores, because Google has been explicit that it treats a hyphen as a word separator and an underscore as a joiner, and keep slugs short. A slug is not a place to repeat the whole title, and once a URL is published, changing it costs you every link pointing at it.