Function content_type_for 

pub fn content_type_for(path: &str) -> &'static str

The content type largo serves a path as — the table largo serve and largo build both use.

Public so mime_single_source_lock asks the REAL table rather than a copy, and can hold it against static.lg’s contentTypeFor, which is what a DEPLOYED LOGOS program answers with. The two had already drifted (text/css against text/css; charset=utf-8, and six types static.lg did not know at all), which means a file typed correctly in development and wrongly in production.