refactor: 복사 코드 함수화

server/Session.cpp

@@ -3,6 +3,7 @@
 #include "SessionManager.h"
 #include <boost/asio/co_spawn.hpp>
 #include <boost/asio/detached.hpp>
+#include <cstring>
 
 Session::Session(tcp::socket socket) : socket_(std::move(socket)) {}
 
@@ -21,6 +22,15 @@ uint32_t Session::GetSwordLevel() const { return swordLevel_; }
 
 void Session::Start() { DoReadHeader(); }
 
+void Session::SendPacket(PacketID id) {
+  PacketHeader header;
+  header.id = static_cast<uint16_t>(id);
+  header.size = 0;
+  std::vector<uint8_t> buffer(sizeof(PacketHeader));
+  std::memcpy(buffer.data(), &header, sizeof(PacketHeader));
+  Send(buffer);
+}
+
 void Session::Send(std::span<const uint8_t> data) {
   auto self(shared_from_this());
   boost::asio::post(