Function get_object_text 

pub async fn get_object_text(
    client: &Client,
    bucket: &str,
    key: &str,
    max_bytes: u64,
) -> Result<TextPayload, AppError>

Fetch the first max_bytes bytes of bucket/key as a UTF-8 string.

Uses a Range: bytes=0-<max_bytes-1> request so the backend never buffers more bytes than needed for the preview.

Errors

• AppError::AccessDenied — s3:GetObject permission denied.
• AppError::NotFound — bucket or key does not exist.
• AppError::Network — any other SDK or transport error.