pub fn fetch(conn: &Connection, id: &str) -> Result<Option<String>>Expand description
Fetch + decompress the transcript identified by id. Returns
Ok(None) when no row matches; callers treat that as “transcript
expired or never existed” and surface a structured error upstream.
§Errors
Returns an error when the row exists but the blob cannot be decoded (corrupt blob, OOM during decompression) or when the decompressed bytes are not valid UTF-8.