Bug: UdpSocket::bind().unwrap() in constructor can panic

[fasuizu-br]

Description

In SntpRequest::new(), the UDP socket bind uses .unwrap():

pub fn new() -> SntpRequest {
    let sntp = SntpRequest {
        socket: UdpSocket::bind("0.0.0.0:0").unwrap(),
        // ...
    };

If the bind fails (e.g., no network, permission denied, all ephemeral ports exhausted), this causes an unrecoverable panic instead of a graceful error.

Suggested fix

Change the constructor to return Result:

pub fn new() -> io::Result<SntpRequest> {
    Ok(SntpRequest {
        socket: UdpSocket::bind("0.0.0.0:0")?,
        // ...
    })
}

Note: This is a breaking API change. Alternatively, document that new() may panic, or provide a try_new() method.

Also, "0.0.0.0:0" only binds to IPv4. For IPv6 support, consider binding to [::]:0 or providing an option to choose.