Remove epoll instances config

src/config.hpp

@@ -40,10 +40,8 @@ struct ServerConfig {
   /// Maximum size in bytes for incoming HTTP requests (default: 1MB)
   int64_t max_request_size_bytes = 1024 * 1024;
   /// Number of I/O threads for handling connections and network events
+  /// Each I/O thread gets its own dedicated epoll instance
   int io_threads = 1;
-  /// Number of epoll instances to reduce epoll_ctl contention (default:
-  /// io_threads, max: io_threads)
-  int epoll_instances = 1;
   /// Event batch size for epoll processing
   int event_batch_size = 32;
   /// Maximum number of concurrent connections (0 = unlimited)