Add optional reason message and code to WebSocket.close

[Yoplitein]

Not sure why the payload length is limited to 125 bytes. Regular messages can be longer, so it doesn't seem to be an issue with vibe code. I found no mention of such a limit for close frames in the RFC.

[s-ludwig]

According to the RFC, the status code should match the codes in section 7.4. For that reason and to avoid a dynamic memory allocation in the default case, I'd wrap the new code in an if (code != 0). I'd also change the order of parameters, because the code must always be set properly if a message is given, but not vice-versa. Otherwise looks good.

[s-ludwig]

The 125 byte limit is mentioned in Section 5.5:

All control frames MUST have a payload length of 125 bytes or less
and MUST NOT be fragmented.

[Yoplitein]

The 125 byte limit is mentioned in Section 5.5:

Ah. I guess I didn't look well enough.

I'd wrap the new code in an if (code != 0). I'd also change the order of parameters

Done and done. Also rebased, so the builds should pass now.

[s-ludwig]

Thanks!