pub fn read_secret_file(path: &str) -> Result<String, String>Expand description
Read one secret file (DW-045): the whole file as UTF-8 with a SINGLE
trailing newline trimmed (\n or \r\n — the mounted-secret-file
convention; interior newlines are preserved), bounded at
MAX_SECRET_FILE_BYTES. Shared by the config grammar and the
FileSecretSource extension impl so the two cannot drift. The error
names the path, never any content.