refactor: repartition server-side and client-side code

app/.client/components/chat/ScreenshotStateManager.tsx

@@ -0,0 +1,22 @@
+import { useEffect } from 'react';
+
+interface ScreenshotStateManagerProps {
+  setUploadFiles?: (files: File[]) => void;
+  uploadFiles: File[];
+}
+
+export const ScreenshotStateManager = ({ setUploadFiles, uploadFiles }: ScreenshotStateManagerProps) => {
+  useEffect(() => {
+    if (setUploadFiles) {
+      (window as any).__UPAGE_SET_UPLOADED_FILES__ = setUploadFiles;
+      (window as any).__UPAGE_UPLOADED_FILES__ = uploadFiles;
+    }
+
+    return () => {
+      delete (window as any).__UPAGE_SET_UPLOADED_FILES__;
+      delete (window as any).__UPAGE_UPLOADED_FILES__;
+    };
+  }, [setUploadFiles, uploadFiles]);
+
+  return null;
+};