Fix/统一修复modal样式失效 (#122)

之前遇到几次弹窗的样式不生效,bug 现在在画布agent的删除对话弹窗又出现了,
这个pr把类似的修改集中到最下层的UnifiedModal,适用于所有的modal,
一些特殊的modal有特殊处理.

画布agent的删除对话弹窗
![shotmd-1785399342.jpg](/attachments/d63d7dc6-bf7e-4f13-bfe8-bc4716cd798f)

---------

Co-authored-by: 段舒康 <kdletters@qq.com>
Reviewed-on: http://192.168.35.82/git/GenarrativeAI/Genarrative/pulls/122
Reviewed-by: 段舒康 <kdletters@qq.com>
Co-authored-by: 王德宇 <kvtodev@outlook.com>
Co-committed-by: 王德宇 <kvtodev@outlook.com>

src/components/common/PlatformReportDialog.test.tsx

@@ -10,6 +10,10 @@ vi.mock('../../services/clipboard', () => ({
   copyTextToClipboard: vi.fn(),
 }));
 
+vi.mock('../auth/AuthUiContext', () => ({
+  useAuthUi: () => ({ platformTheme: 'dark' }),
+}));
+
 afterEach(() => {
   vi.clearAllMocks();
 });
@@ -31,6 +35,8 @@ test('renders report fields and copies the joined report lines', async () => {
   );
 
   const dialog = screen.getByRole('dialog', { name: '统一报告' });
+  expect(dialog.parentElement?.className).toContain('platform-theme--light');
+  expect(dialog.parentElement?.className).not.toContain('platform-theme--dark');
   expect(within(dialog).getByText('拼图草稿 puzzle-session-1')).toBeTruthy();
   expect(within(dialog).getByText('已完成')).toBeTruthy();