fix(socket): accept/socket 非 Windows 分支补齐 u64→INT 显式窄化（out_client.fd / return / out_sock.fd）

socket.vp

@@ -337,11 +337,11 @@ class Socket:
         client_fd: INT = INT(accept(self.fd, &addr, &addrlen))
         if client_fd == SOCKET_ERROR:
             return SOCKET_ERROR
-        out_client.fd = client_fd
+        out_client.fd = INT(client_fd)
         out_client.family = self.family
         out_client.type = self.type
         out_client.protocol = self.protocol
-        return client_fd
+        return INT(client_fd)
 
     def settimeout(self, timeout_ms: INT) -> INT:
         """Set timeout for receive and send operations (milliseconds).
@@ -408,7 +408,7 @@ def SocketCreate(family: INT, type: INT, protocol: INT, out_sock: Socket*) -> IN
         if fd == win32.winsock2.INVALID_SOCKET: return -1
     else:
         fd: INT = INT(socket(family, type, protocol))
-        out_sock.fd = fd
+        out_sock.fd = INT(fd)
         if fd == INVALID_SOCKET: return -1
     return 0