Download the .txt of a language file

Answers the .txt of a language file: text/plain; charset=UTF-8 with a Content-Disposition of language_file.txt. One of the two routes of this API that are a GET, whose success is not a JSON envelope and that have no MCP tool of their own.

TWO WAYS IN, AND ONE OF THEM IS ENOUGH. token is the signed link /v1/language-files/get publishes as download_url: it carries the account and the file inside it, needs no Authorization header -- which is what lets an assistant hand it to a person -- and expires 900 seconds after it was minted, with no way to revoke it before that. language_file_key is the form a script uses, with the Bearer of the account. A request carrying both is served by the token.

THE FILE IS REBUILT, not stored: the English master of the platform, with its sections, its comments and its keys, carrying the literals of this file. That is what the download of the application answers and what /v1/language-files/create reads back, so the round trip is closed. The sixteen files of the platform are downloadable too.

Everything that is not the file comes back in the envelope of the rest of the API (401, 404, 429). A POST to this path is ENDPOINT_NOT_FOUND, and a HEAD is refused with 405.