just redo all of it from scratch

lib/mcp/server/transports/stdio.rb

@@ -0,0 +1,35 @@
+# frozen_string_literal: true
+
+require_relative "../../shared/transport"
+require "json"
+
+module MCP
+  module Transports
+    class StdioTransport < Transport
+      def initialize(server)
+        @server = server
+        @open = false
+        $stdin.set_encoding("UTF-8")
+        $stdout.set_encoding("UTF-8")
+        super
+      end
+
+      def open
+        @open = true
+        while @open && (line = $stdin.gets)
+          handle_json_request(line.strip)
+        end
+      end
+
+      def close
+        @open = false
+      end
+
+      def send_response(message)
+        json_message = message.is_a?(String) ? message : JSON.generate(message)
+        $stdout.puts(json_message)
+        $stdout.flush
+      end
+    end
+  end
+end