Update some inaccuracies in markdown files

design.md

@@ -118,7 +118,7 @@ Ultra-fast memory allocator optimized for request/response patterns:
 - **Configurable epoll instances** to eliminate kernel-level epoll_ctl contention (default: 2, max: io_threads)
 - **Round-robin thread-to-epoll assignment** distributes I/O threads across epoll instances
 - **Connection distribution** keeps accepted connections on same epoll, returns via round-robin
-- **Factory pattern construction** via `Server::create()` ensures proper shared_ptr semantics
+- **Factory pattern construction** via `Server::create()` ensures you can only get a `Ref<Server>`
 - **Safe shutdown mechanism** with async-signal-safe shutdown() method
 - **Connection ownership management** with automatic cleanup on server destruction
 - **Pluggable protocol handlers** via ConnectionHandler interface
@@ -383,18 +383,7 @@ auto server = Server::create(config, handler);
 
 #### Connection Creation (Server-Only)
 
-```cpp
-// Only Server can create connections (using private friend method)
-class Server {
-private:
-  auto conn = Connection::createForServer(addr, fd, id, handler, weak_from_this());
-};
-
-// No public way to create connections - all these fail:
-// auto conn = Connection::create(...);        // ERROR: no such method
-// Connection conn(addr, fd, id, handler, server);  // ERROR: private constructor
-// auto conn = std::make_unique<Connection>(...);   // ERROR: private constructor
-```
+Only Server can create connections (using private constructor via friend access)
 
 ### ConnectionHandler Implementation Patterns