fix: remove unused useMemo import and fix optimisticMessage type mismatch

Co-authored-by: Cursor <cursoragent@cursor.com>

src/components/UiComponents/Messages/ChatMessages/ChatMessage.tsx

@@ -1,4 +1,4 @@
-import React, { useState, useMemo } from 'react';
+import React, { useState } from 'react';
 import ReactMarkdown from 'react-markdown';
 import remarkGfm from 'remark-gfm';
 import { FaExclamationTriangle } from 'react-icons/fa';

src/hooks/playground/useDashboardInputForm.ts

@@ -330,7 +330,7 @@ export function useDashboardInputForm(instanceId: string) {
       );
       if (!firstBackendMsg) {
         // Backend "first" message not yet arrived - show optimistic message
-        allMessages.push(optimisticMessage);
+        allMessages.push({ ...optimisticMessage, documents: (optimisticMessage as any).documents });
       }
       // If firstBackendMsg exists, the useEffect above will clear optimistic on next render
     }