feat(tcp): a failed send or receive says which errno it failed with

Send() and the receives threw a bare std::runtime_error with the
strerror text, so a caller that reports the cause the way Python does -
"the connection broke ([Errno 104] Connection reset by peer)", which a
language model reads in Crafter.Review's SQL helper output - could not
tell the code. They throw SocketErrorException now, as a failed connect
already does: kind System, the errno, and the same message, still a
std::runtime_error. A receive timeout stays SocketTimeoutException and
a closed peer SocketClosedException.

ShouldReportIoErrors: a peer that resets the connection (SO_LINGER 0)
fails the next receive with ECONNRESET and a send into it with EPIPE
or ECONNRESET.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

interfaces/Crafter.Network-ClientTCP.cppm

@@ -45,8 +45,8 @@ namespace Crafter {
 		Resolver,
 	};
 
-	// A resolve, a socket() or a connect that failed, with the code it failed
-	// with. what() is the text ClientTCP has always thrown, and catching
+	// A resolve, a socket(), a connect, a send or a receive that failed, with
+	// the code it failed with. what() is the text ClientTCP has always thrown, and catching
 	// std::runtime_error still catches it; the code is for callers that
 	// report the cause in their own words — a Python-style
 	// "[Errno 111] Connection refused", say — and would otherwise have to