Don't copy every byte read into arena

src/connection.cpp

@@ -47,11 +47,7 @@ void Connection::appendMessage(std::string_view s, bool copyToArena) {
   }
 }
 
-std::string_view Connection::readBytes(size_t /*max_request_size*/,
-                                       size_t buffer_size) {
-  // Use Variable Length Array for optimal stack allocation
-  char buf[buffer_size];
-
+std::string_view Connection::readBytes(char *buf, size_t buffer_size) {
   int r = read(fd_, buf, buffer_size);
   if (r == -1) {
     if (errno == EINTR || errno == EAGAIN) {
@@ -63,11 +59,7 @@ std::string_view Connection::readBytes(size_t /*max_request_size*/,
   if (r == 0) {
     return {}; // EOF - let server handle connection cleanup
   }
-
-  // Copy data to arena for persistent storage
-  char *arena_data = arena_.allocate<char>(r);
-  std::memcpy(arena_data, buf, r);
-  return {arena_data, size_t(r)};
+  return {buf, size_t(r)};
 }
 
 bool Connection::writeBytes() {