fix stale state in /rewind

packages/core/src/context/chatCompressionService.test.ts

@@ -196,7 +196,9 @@ describe('ChatCompressionService', () => {
     } as unknown as Config;
 
     vi.mocked(getInitialChatHistory).mockImplementation(
-      async (_config, extraHistory) => extraHistory || [],
+      async (_config, extraHistory?: readonly Content[]) => [
+        ...(extraHistory || []),
+      ],
     );
   });