code review followup for compress command (#1097)

Followup to https://github.com/google-gemini/gemini-cli/pull/986

packages/cli/src/ui/hooks/slashCommandProcessor.ts

@@ -760,6 +760,8 @@ Add any other context about the problem here.
             type: MessageType.COMPRESSION,
             compression: {
               isPending: true,
+              originalTokenCount: null,
+              newTokenCount: null,
             },
           });
           try {