S13.09: WinsockTcpStream — Windows TCP transport

[DavidCozens]

Parent epic: #40

Goal

Implement a Winsock TCP stream (SolidSyslogWinsockTcpStream) using winsock2.h, providing the SolidSyslogStream interface. The Windows TCP path mirrors SolidSyslogPosixTcpStream (extracted in S13.08 and hardened in S12.08) with platform-appropriate type and error-handling adjustments.

Acceptance criteria

• Platform/Windows/Interface/SolidSyslogWinsockTcpStream.h — Create/Destroy, SolidSyslogWinsockTcpStreamStorage, SOLIDSYSLOG_WINSOCK_TCP_STREAM_SIZE
• Platform/Windows/Source/SolidSyslogWinsockTcpStream.c — implementation using socket, connect, send, recv, closesocket, setsockopt (TCP_NODELAY + SO_SNDTIMEO)
• Platform/Windows/Source/SolidSyslogWinsockTcpStreamInternal.h — UT_PTR_SET test seam with WinsockTcpStream_* namespaced forwarders (avoids colliding with Winsock_socket/Winsock_closesocket already exported by SolidSyslogWinsockDatagram)
• Tests/Support/WinsockFake.{h,c} extended with connect, send, recv, setsockopt fakes plus configuration knobs (mirrors S12.08 SocketFake additions)
• Tests/SolidSyslogWinsockTcpStreamTest.cpp — port of SolidSyslogPosixTcpStreamTest.cpp adjusted for Winsock (no EINTR retry, flags = 0 instead of MSG_NOSIGNAL, generic send-error in place of EAGAIN-specific test)
• CMake: sources added when SOLIDSYSLOG_WINSOCK is true; library already links ws2_32
• All CI checks green including windows-build-and-test
• Caller manages WSAStartup / WSACleanup — documented as precondition (matches existing Winsock pattern)

Prep refactor (same branch, separate commit)

SOLIDSYSLOG_TCP_DEFAULT_PORT and SOLIDSYSLOG_UDP_DEFAULT_PORT consolidated into Core/Interface/SolidSyslogTransport.h so the new Winsock TCP stream does not duplicate the constant. Both are platform-agnostic IANA/RFC facts and naturally pair with the SolidSyslogTransport enum already in that header. SolidSyslogUdpSender.h, SolidSyslogPosixTcpStream.h, and the new SolidSyslogWinsockTcpStream.h #include "SolidSyslogTransport.h" so existing callers continue to get the constants transitively.

Design decisions

• Implements the SolidSyslogStream interface extracted in S13.08 (S13.08: Extract Stream abstraction, provide PosixTcpStream #134); production logic mirrors PosixTcpStream after the S12.08 error-edge work
• SOCKET (unsigned UINT_PTR) instead of int; INVALID_SOCKET instead of -1; closesocket() instead of close(); Winsock send/recv return int instead of ssize_t
• SO_SNDTIMEO: DWORD milliseconds on Winsock instead of POSIX struct timeval; same level/optname so tests can assert on the pair via HasSetSockOpt
• EINTR retry path pruned — Winsock send() has no signal-interruption semantics
• MSG_NOSIGNAL removed — Winsock does not generate SIGPIPE, flags pass as 0
• No WSAGetLastError() needed — vtable contract is bool; caller already handles "false → close + reconnect → store-and-forward replays" identically to PosixTcpStream
• Test seam follows the WinsockDatagram / WinsockResolver precedent (UT_PTR_SET on file-scope function-pointer forwarders) but uses WinsockTcpStream_* namespaced symbols to avoid linker collisions with the un-namespaced Winsock_* already exported by WinsockDatagram
• No #ifdef in source files — platform differences handled entirely in CMake

Out of scope (deferred to S13.10)

• Wiring TCP into Example/Windows/SolidSyslogWindowsExample.c
• BDD scenario for Windows TCP delivery to syslog-ng
• End-to-end exercise via windows-build-and-test

Context

Completes the Windows TCP transport path. Combined with WinsockResolver (S13.04) and the Stream abstraction (S13.08), this enables TCP syslog delivery on Windows. S13.10 then proves the path end-to-end against syslog-ng in BDD and wires it into the Windows example.