Add unix socket listening mode

src/config.hpp

@@ -14,6 +14,8 @@ struct ServerConfig {
   std::string bind_address = "127.0.0.1";
   /// TCP port number for the server to listen on
   int port = 8080;
+  /// Unix socket path (if specified, takes precedence over TCP)
+  std::string unix_socket_path;
   /// Maximum size in bytes for incoming HTTP requests (default: 1MB)
   size_t max_request_size_bytes = 1024 * 1024;
   /// Number of accept threads for handling incoming connections