Remove transport-specific code from server

lib/mcp/server.rb

@@ -98,14 +98,6 @@ module MCP
       @prompts[prompt.name_value] = prompt
     end
 
-    def handle_rack_request(request)
-      @transport.handle_request(request)
-    end
-
-    def close
-      @transport.close
-    end
-
     def resources_list_handler(&block)
       @capabilities.support_resources
       @handlers[Methods::RESOURCES_LIST] = block