Function content_hash 

pub fn content_hash(text: &str) -> String

A stable sentinel over an arbitrary generated text artefact.

Used for playlists, whose .m3u8 body is generated rather than fetched: the hash is taken over the full rendered text, so the playlist name, the member order, and every member’s relative path, title, and duration all feed it (HARDENING B1: a change to anything that ends up in the file changes the hash and so triggers a rewrite). Because the render is deterministic, the hash is stable across runs and platforms.