fix(design): preserve command outcome certainty

tests/unit/image-canvas-page.test.tsx

@@ -1,5 +1,6 @@
-import { fireEvent, render, screen, within } from '@testing-library/react';
+import { fireEvent, render, screen, waitFor, within } from '@testing-library/react';
 import { beforeEach, describe, expect, it, vi } from 'vitest';
+import { ImageWorkspaceApiError } from '@/lib/image-workspace';
 import { ImageCanvas } from '@/pages/ImageCanvas';
 import { useAuthStore } from '@/stores/auth';
 import { useImagePromptMuseumStore } from '@/stores/image-prompt-museum';
@@ -11,6 +12,12 @@ import {
   designWorkspaceFixture,
 } from '../fixtures/design-workspace-v2';
 
+const { toastErrorMock } = vi.hoisted(() => ({ toastErrorMock: vi.fn() }));
+
+vi.mock('sonner', () => ({
+  toast: { error: toastErrorMock, success: vi.fn() },
+}));
+
 vi.mock('@/lib/image-workspace', async (importOriginal) => {
   const original = await importOriginal<typeof import('@/lib/image-workspace')>();
   return {
@@ -138,6 +145,26 @@ describe('youth AI Design Canvas page', () => {
     expect(actions.sendChat).not.toHaveBeenCalled();
   });
 
+  it('shows the safe reasoner failure instead of claiming the message was not sent', async () => {
+    const { actions } = prepareWorkspace();
+    actions.sendChat.mockRejectedValueOnce(new ImageWorkspaceApiError(
+      502,
+      'design_reasoner_invalid',
+      'AI 没有整理好这次想法，请再试一次',
+    ));
+    render(<ImageCanvas />);
+
+    fireEvent.change(screen.getByRole('textbox', { name: '告诉 AI 你想创作什么' }), {
+      target: { value: '画一只会做饭的机器人' },
+    });
+    fireEvent.click(screen.getByRole('button', { name: '发送消息' }));
+
+    await waitFor(() => {
+      expect(toastErrorMock).toHaveBeenCalledWith('AI 没有整理好这次想法，请再试一次');
+    });
+    expect(toastErrorMock).not.toHaveBeenCalledWith('消息没有发出去，请再试一次');
+  });
+
   it('explains an unknown accepted result without suggesting a second production', () => {
     const { actions } = prepareWorkspace();
     useImageWorkspaceStore.setState({