Function decode_entities 

pub fn decode_entities(s: &str) -> String

Decode all HTML entities in a string.

Handles named entities (&), decimal (©), hex (©), Windows-1252 C1 range mapping, and semicolon-optional entities.

assert_eq!(deformat::html::decode_entities("Café"), "Café");
assert_eq!(deformat::html::decode_entities("© 2026"), "\u{00A9} 2026");