refactor: 迁移 i18n 系统从 react-i18next 到 chrome.i18n

- 移除 react-i18next、i18next 及相关依赖
- 删除旧的 i18n/ 目录和 useLazyTranslation 工具
- 新增 utils/chromeI18n.ts 类型安全 wrapper（useI18n Hook + getMessage）
- 生成 public/_locales/{zh,en}/messages.json（298 个翻译 key）
- 批量更新 39+ 组件文件的导入和翻译调用
- 转换翻译键格式：namespace:key → namespace_key
- 修复 ErrorBoundary/PageErrorBoundary 从 withTranslation HOC 改为直接调用 getMessage
- 更新 vitest.setup.ts mock 加载实际翻译文本
- 修复 11 个测试文件的断言以匹配中文翻译
- TypeScript、ESLint、547 项测试全部通过

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

components/__tests__/TopBar.test.tsx

@@ -55,18 +55,18 @@ describe('TopBar 组件', () => {
     it('不在 dashboard 时应渲染返回按钮', () => {
       mockRouterValue.currentPage = 'timestamp';
       renderWithProvider(<TopBar onOpenOptions={vi.fn()} />);
-      expect(screen.getByLabelText('common:buttons.back')).toBeInTheDocument();
+      expect(screen.getByLabelText('返回')).toBeInTheDocument();
     });
 
     it('在 dashboard 上不应渲染返回按钮', () => {
       mockRouterValue.currentPage = 'dashboard';
       renderWithProvider(<TopBar onOpenOptions={vi.fn()} />);
-      expect(screen.queryByLabelText('common:buttons.back')).not.toBeInTheDocument();
+      expect(screen.queryByLabelText('返回')).not.toBeInTheDocument();
     });
 
     it('应渲染设置按钮', () => {
       renderWithProvider(<TopBar onOpenOptions={vi.fn()} />);
-      expect(screen.getByLabelText('common:buttons.settings')).toBeInTheDocument();
+      expect(screen.getByLabelText('设置')).toBeInTheDocument();
     });
   });
 
@@ -75,7 +75,7 @@ describe('TopBar 组件', () => {
       const handleOpenOptions = vi.fn();
       renderWithProvider(<TopBar onOpenOptions={handleOpenOptions} />);
 
-      fireEvent.click(screen.getByLabelText('common:buttons.settings'));
+      fireEvent.click(screen.getByLabelText('设置'));
       expect(handleOpenOptions).toHaveBeenCalledTimes(1);
     });
 
@@ -83,7 +83,7 @@ describe('TopBar 组件', () => {
       mockRouterValue.currentPage = 'timestamp';
       renderWithProvider(<TopBar onOpenOptions={vi.fn()} />);
 
-      fireEvent.click(screen.getByLabelText('common:buttons.back'));
+      fireEvent.click(screen.getByLabelText('返回'));
       expect(mockRouterValue.goBack).toHaveBeenCalledTimes(1);
     });
   });