Fix build: embedded Tor linking, UPnP guard, LogPrintf, socket types

- CMakeLists: add --start-group linking for libtor.a and its deps
  (libevent, openssl, zlib, lzma, zstd) with --allow-multiple-definition
  for mixed static/dynamic OpenSSL on Windows
- CMakeLists: define USE_UPNP=0 only when USE_UPNP is off (not via
  #ifdef-incompatible define)
- net.cpp: guard USE_UPNP reference with #ifdef for builds without UPnP
- rpcwallet.cpp: replace nonexistent LogPrintf with printf
- tor_embedded.cpp: fix SOCKET type mismatch on Windows (SOCKET vs int)
- .gitignore: add testnet-sync/ directory

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/tor/tor_embedded.cpp

@@ -165,8 +165,13 @@ bool CTorEmbedded::Start(int socks, int hsPort, bool enableHiddenService)
         }
 
         // Quick port check
+#ifdef WIN32
+        SOCKET sock = socket(AF_INET, SOCK_STREAM, 0);
+        if (sock != INVALID_SOCKET) {
+#else
         int sock = socket(AF_INET, SOCK_STREAM, 0);
         if (sock >= 0) {
+#endif
             struct sockaddr_in addr;
             memset(&addr, 0, sizeof(addr));
             addr.sin_family = AF_INET;