Always use struct

src/server.cpp

@@ -1,6 +1,5 @@
 #include "server.hpp"
-#include "connection.hpp"
-#include "connection_registry.hpp"
+
 #include <csignal>
 #include <cstdio>
 #include <cstdlib>
@@ -17,6 +16,9 @@
 #include <unistd.h>
 #include <vector>
 
+#include "connection.hpp"
+#include "connection_registry.hpp"
+
 // Static thread-local storage for read buffer (used across different functions)
 static thread_local std::vector<char> g_read_buffer;