fix(ui): ensure rationale renders before tool calls (#17043)

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

@@ -923,6 +923,10 @@ export const useGeminiStream = (
         }
       }
       if (toolCallRequests.length > 0) {
+        if (pendingHistoryItemRef.current) {
+          addItem(pendingHistoryItemRef.current, userMessageTimestamp);
+          setPendingHistoryItem(null);
+        }
         await scheduleToolCalls(toolCallRequests, signal);
       }
       return StreamProcessingStatus.Completed;
@@ -940,6 +944,9 @@ export const useGeminiStream = (
       handleChatModelEvent,
       handleAgentExecutionStoppedEvent,
       handleAgentExecutionBlockedEvent,
+      addItem,
+      pendingHistoryItemRef,
+      setPendingHistoryItem,
     ],
   );
   const submitQuery = useCallback(